Previous related posts:
2 color ribbed brioche stitch on Brother knitting machine 1
Geometric shapes on ribber fabrics with tuck stitches 1
Geometric shapes on ribber fabrics with tuck stitches 2; knitting with 4 carriages
The last post on using Gimp: 2021/07/18/gimp-update-for-mac-2/
The method for color separation used for mosaics
The sources of inspiration from hand knitting or industrial knitting machine designs are endless. There are many features that simply cannot be duplicated, sometimes compromises can be reached that can achieve only imitations of the original. To my mind when knitting garments or long pieces the greater the degree of automation, the less likely one is to have patterning errors occur, in ribber fabrics, they are also more complicated to correct than single bed knitting.
I recently came across a pin of a Ravelry hand knit pattern which led to my return to this topic once more, including perhaps the addition of more colors. 
The plan is to create a repeat which may be knit using color changes every 2 rows. Each design row knits each color twice, so the standard built-in KRC separation is not a consideration, though the same cam settings may be used in those fabrics as well.
The required color separation has been discussed in several posts on the various forms of DBJ, a review:
The initial test repeat is 18 stitches by 44 rows, designed using 2 X 2 blocks, to begin with. How it might appear knit in fair isle: 
Transitions in charting visualizations:
A: FI repeat with pattern progression in two-row increments
B: every even-numbered row beginning with row 2 is color reversed
C: B repeat is doubled in length to 18X88 for initial samples
D: repeat adjustment for a first try at introducing 2 additional colors 
End needle selection is canceled, the first and last needles are in work on each side on the ribber knitting every row, the first preselection row is from right to left, cam buttons are set after the left side is reached. Knitting in these samples began with the blue yarn in the number 2 position in the color changer. The ribber remains set for knitting in both directions throughout, the images on the right do not reflect the amount of surface 3D textures.
with the main bed set to tuck in both directions: 
Lock settings are easier to achieve on the Passap than switching out cam buttons in Brother machines. This was knit using 4 carriages. Color one knits with the main bed set to tuck both ways, color two knits with the main bed set to slip both ways. The slip stitch reduces the width of the fabric considerably 
Here each color alternately tucks and slips. The choice of cam buttons matters, tucking first from left to right, slipping from right to left, with cam buttons set COL after the first preselection row 
This last cam setting appears to my eye to produce a texture “close enough” to the inspiration fabric. Attempting to add more colors: the repeat, D, is still 18 X 88 but is now shifted slightly. 
Somehow the slip cam button was not set, so the knit carriage tucked in one direction while knitting in the other. I am vaguely reminded of illusion knits. Considering altering both the color choices and placements again. 
A way to imagine exact color change placements beginning with solid colors repeats once more, which can be followed by new color separations. 
The existing repeat may be reduced further to 18 X 64, eliminating some of those extra rows in the center of the chevron shape 
The new BW image, tiled: 
Whether or not the design is intended to retain chevron shapes in alternating textures, actions may be plotted pre knitting in any way that visually makes sense to the person designing the pattern and tools available to them. 
Reversing the png so that the more textured stitches will begin with the color in yarn position 1
Using either repeat, color changes now occur after every 32 rows knit. Another color change location clue is in the needle selection change above and immediately following the red border in the chart on the left. 
Adding colors can be planned cautiously or allowed to happen randomly depending on the preferences of the designer and end-use. Ribber fabric designs are not visible until several inches have been knit, too late to catch color sequence errors. Some machines allow for memo placements or sounds to help track color changes, but only within the initially programmed repeats. A quick spreadsheet can provide customizable checkboxes or added information. For an attempt to retain chevron shapes in different textures: 
When using 3 colors, rather than 4, the texture of the zigzags on any specific color, will vary in placement. It is easy to change colors in any chart to approximate those that will actually be used in the knitting. 
Proof of concept: each of my yarns is slightly different in both thickness or fiber content from the others, which can be a drawback in resulting textures. As in any 2 color dbj, if 4 consequent rows are knit in one of two colors the positive and negative portions of the image reverse, as seen at the top of the swatch. The green was not intended to be used originally, the white yarn simply ran out. Such accidents at times may provide pleasant improvements. There is bleed-through of each color behind the other in the tighter knit areas as well which contributes to visual color blending, noticeable even in the areas with fewer tucked stitches. 
Splitting zig-zags into triangles, working color 1 with color 2, followed by color 3 with color 4 pairings 
A PDF including row numbers and space for notations zig zag
An editable Excel spreadsheet created as an export from numbers zig zag
For Mac owners a Numbers doc. zig zag
A simpler repeat suitable punchcard owners as well using only 2 colors 
The test swatch and observations: patterning was begun with color 2, yellow.
The yellow yarn is 12/16, the maroon is 2/15 in thickness.
The triangle, because slip and tuck stitch settings are used, is compressed in height, while there is enough tuck happening to still make the knit wider.
The pattern is 24 stitches wide, the swatch was knit on 40 needles. Smaller swatches are fine for testing tension and colors. If committing to larger pieces, tests on at least 100 stitches by 100 rows are needed for gauge calculations in any double bed work or very textured patterns on the single bed. On some occasions when a far larger number of needles are in use, problems may turn up that require going back to the drawing board in terms of items ie tension settings, weight used, etc.
A: patterning was begun with thicker yarn, the yellow, in color changer position 2, both yarns are 100% wool
B: KCI, end needle selection on, a 2 color “beaded” edge is created
C: KCII, end needle selection canceled, patterning occurs on end needles
D: transferring to the top bed and using the standard latch tool bind off for these fabrics is far too tight 
The tiled repeat, 24X48, does keep the stitch quality constant for both colors, Assumptions based on optics of tiling are not always accurate clues to potential patterning errors, here those darker lines are part of the actual design 
Continuing on a 24 stitch repeat, the original design may be rendered at double height and separated once more, doubling the separation height to 96 rows 
There are days when either or both machine and knitter need a break. At the start of the first swatch, the cam buttons were not set, resulting in plain knit stripes. At its top, the purple did not get picked up properly from the color changer, and the knitting of course fell off the machine. On a second try, the same issue happened again with the purple yarn. Multiple incidences of such events were fondly nicknamed “dropitis” by my students. The test is on 24 stitches, the width of a single repeat, the triangles are much more balanced in size, this knitter is putting this pattern to rest. 
Another try at the diamond shapes that began this topic. The first .png
when tiled appeared to not have enough space between the shapes, was amended to this 
the differences when tiled 
the color separation can happen completely within Gimp using color invert 
the white yarn is an acrylic, slightly thicker than the purple toned one. Sometimes simply exchanging yarn positions can change the qualities of the overall fabric. 
The repeat begins with 2 blank rows. To achieve the tighter white shape as opposed to the honeycomb purple one, at the start of the repeat that color needs to be in use on rows where knit stitches happen as the KC, set on slip to the right, knits needles brought forward to D position. Red in this chart segment marks pertinent rows
Both with hand knits and commercial knits because of the hand actions possible on both sides in the first, and as many as 4 beds selecting and knitting on the other may be in use at the same time with more complex needles as well, there are fabrics that are difficult or even impossible to duplicate. There often are obvious differences in the results, but the journey may still yield results that are pleasing and worth pursuing. 
Another even more complex inspiration from a sweater attributed to Falke, Spring 20 collection, using similar stitch structures, but in addition, also transferring stitches between beds exposing a purl striped ground.
For some reason, I found the commands erratic when working on the translated version of the site, and fared much better in the original language publication.
Screengrab the final image surrounded by extra white cells, and open it in GIMP.
Getting a preview of how a finished garment might appear, here the tiled version is 192 pixels in width and one may glean some idea as to whether that repeat should ever really be used in a sweater or even a blanket. Further image scaling or cropping can happen based on the knit gauge. 
A very quick rendering imagining pattern and color placements using a simple sweater outline 
Collections of every other needle repeats for processing with a similar approach may be found in these volumes, available for free download
Both volumes include accompanying swatch illustrations.
For a better, printed match size, after capturing the image from the PDF for a single page outside image edges, opening it in Gimp, and cropping it to content, it is then possible to scale the results to measurements of a factory punchcard equal in width and adjusted for the number of rows in the image. My card required print measurements were 14.1cm by 26.1. Scaling executed with an aspect ratio that is too long. 
breaking the chain-link, removing size constraints 
The results with the selection of even rows simply shift the result up a row 
Test in your version of the program to see whether releasing the shift key prior to making edits changes them. Either way, being consistent in the choice makes for less confusing results. Experimentation takes a matter of seconds.
using the rectangle tool, either odd or even rows may be chosen, remaining consistent for the height of the repeat in a scale to suit the end fabric goal. Here the original file is lengthened X2
working with the original file lengthened x4. The selections can happen on every row or every other, whether singly or in pairs. Note the difference between making the first selection on the first pair of rows or the second. 
2021: 
single click on the filing cabinet icon on the right, 
double click on the patterns folder, and its own window will appear, 
and the new folder will be added within the brushes one 
For future use, any saved brush may be dragged and dropped into the named personal pattern folder icon, or into the folder after it has been expanded or opened in its own window. My opened brush folder 
When exporting self-drawn brushes, the option is offered for adding spacing surrounding the shape, here a 10% addition was chosen 
To save personal patterns, instead of choosing the file cabinet icon in preferences, one may choose the folder icon, following a similar series of steps to those above, including verifying the contents of the newly created folder 
Use Windows, Dockable Dialogues, choose Pattern. The patterns will show on the right
Click on the paint bucket, then on the pattern you wish to use on right, hover over the canvas with the paint tool, click on it and the image will fill in the chosen pattern.
Foreground and Background colors: in RGB Mode, click on the foreground color to select a new color for the grid, click OK 
This command is found in the image menubar through 
You can create as many guides as you like, positioned wherever you like.
Built-in or custom brushes may be superimposed on a bucket-filled ground. Create an image in the desired width and height, here 24 X 24, and magnify at least X 800 for a grid view.
The color exchange window will appear. Here the white “from color” is left undisturbed. Select the dropper next to the “to color”, then click on the image on the color you wish to change, a palette window will appear. Make your choice, the color exchange window will now have substituted the chosen color for black, click OK, and white design areas are now changed to the chosen blue globally. 
The process may then be repeated with the second color if desired. The color exchange window will show white as the default “from color”. Click on the white bar, choose black from the palette window or use the dropper to select black from the image. The from color will then appear as black. Repeat selection with the dropper from the right of the “to color” bar on any black pixels in the image, choose the color from the palette window to replace it, and the color exchange window will display the new “to color”. Click OK, and job done. 
The process may be repeated multiple times on the same design or used on large-scale ones, giving one some idea as to whether or not to really commit to the estimated colors. 
I recently had reason to review old PC files from my Passap knitting days and came across several cut files that when converted to png format appeared in colors rather than black and white, leading me to experiment with color exchange again. The image for the first experiment is part of a crib blanket by Cheryl Giles
It is possible to colorize images originally drawn in black and white. The color exchange options will remain fixed throughout the process. The image may be worked on continuously and exported when color exchanges are completed, or saved and imported again after each step. The color exchange here happens consistently on the chosen background color, changing that quickly becomes familiar and easy. There are times that the repeat being processed will turn black onscreen, trust in the process and continue.
Developing custom palettes in order to visualize different colorways while using the same repeat:
this window will open with selections for possible palette choices 
click on your choice, then click on the palette icon, and your color choices will appear, click on the white, to create a new background color. 
My success with series of other images in using color exchange has been spotty. Online forums reveal this is a recurrent issue with no clear solutions. Suggestions include stipulating that the cause may be the version of Mac OS in use. Color reductions using 
The image itself may be scaled concurrently to tweak grid border alignments. The final grid size below is 18X18, the image size is shown after scaling from a width of 277 pixels (with a broken link at that time) to a final 270 pixels in width 
The screengrab of the above center, with a superimposed new grid; note the image, in this case, was also offset for better placement, a 3-pixel pencil was used to isolate the border of the possible smallest repeat 
Translating the colored image to BW indexed may take several steps and some clean-up if only Gimp is used to process it. With the colored large-scale isolated repeat, the image is opened in Gimp. The Threshold tool transforms the current layer or the selection into a black-and-white image, where white pixels represent the pixels of the image whose Value is in the threshold range, and black pixels represent pixels with Value out of the threshold range. It may be activated from the pull-down colors menu or from the toolbox. 
Color separations: there are occasions where very small repeats need to be scaled in height only for color separations. I have found such scaling to be inaccurate using the option, such as here, both of the small, single repeat, and in scaling its tiled version. The triangle motif was used in many of my early posts on color separations for DBJ and its backing options. 
The appearance of the final repeat when color is reversed 
Another comparison of the 2 options for altering every other pair of rows in the specific color separation for a mosaic repeat. There is less filling in of cells with a different color, but in large files especially, I feel the result would become far more visually confusing to track. 
Working with potential knit repeats the scale is reduced further. Magnification is useful for the evaluation of repeats. The smallest repeat segments for use on electronic machines may be isolated. The filter, map, and tile option easily verify how the repeats line up overall. Cropping a 24-stitch width and tiling that also visualizes the suitability of the repeat for use on punchcards with the 24-stitch limitation. Grid view helps identify any need for “clean up”.
and a type of symmetry and accompanying settings, click on pencil tool, the motif will appear as on the above right, paste the image on the new canvas, undo and repeat setting adjustments until satisfied with the distribution of motifs.
The 24X50 repeat: 
To decrease crowding, using the original image, the new canvas is now 40X60, with the shift decreased from 12 to 8 pixels. The result did not tile properly when mapped, using magnification 800X with a viewed grid the final repeat, 29X60 was isolated 
Being more deliberate with the math leads to a full, successful repeat 
Using that small triangular 8X8 repeat
Again, preemptive math will yield images that avoid further processing. It is up to the user to recognize any problems, the repeat here needs to and can be isolated correctly from the file on the left, it is actually only 16 rows high. Here the adjusted repeat is created on a 24X16 canvas with the same symmetry settings, and filter/mapped/tiled 
The above repeat was cropped and adjusted to 16 stitch width and 8 row height, the file saved, and the process repeated 
Using symmetry once more, remember to adjust the pencil size. 
I was unable to use color exchange successfully on the above images, but with the saved 2 colors indexed red and white repeat both img2track and ayab appeared to load the repeat successfully. 
The map color exchange was successful using the steps described at the top of the post when beginning with the repeat drawn in a black and white version. 
Nearly all my previous dbj pieces have been knit on a Passap E6000. The 930 experience for such repeats is new to me. With some help from Tanya Cunnigham in reviewing the steps required when using img2track, I returned to cellular automata repeat saved years ago.
That provided an opportunity to decide I preferred the reverse color placement as well as wanting a thicker ply for the white, resulting in twice the fun with 2 colors, and another scrapped sample 
I was able to achieve a reasonable repair on the knit side, but the birdseye pattern on the reverse is a bit scrambled. 
There is also potential for exchanging colors to get a sense of how the pattern might appear in different colorways 
Brother was the first to allow programming from multiple areas on a single mylar sheet. Starting and ending stitches and rows needed to be entered, I got used to drawing boxes for each pattern as seen on the upper right, reducing errors in future knitting. The red lines on the copy highlight the repeat’s border. Mylars were read 13 rows down, punchcard machines7. The equivalent of arrow markings on lace punchcards are provided in the column on the left, which extends over the top of the drawing space by the same number of rows, allowing it to remain visible above the card reader even as the top of the mylar patterning area is reached.
Depending on the electronic model or the software used to download patterns designed for lace, the final image may need to be flipped horizontally. This is true for use on my 930. Creating a template for mesh using numbers: begin with a table with square cells in numbers larger than you might need, ie 24 by 54. The method for doing so has been explained in previous posts. I happen to prefer cell units that measure 20 points by 20. The smallest repeat unit for use on any machine is isolated, shown bordered in red, is 4 stitches wide by 6 rows high, and drawn onto the template. The group of cells in the repeat are selected. If one hovers over any side or top and bottom borders of it, a yellow dot appears. Clicking and dragging on the yellow dot will repeat the full selection to the right, left, up, or down. Here the move is to the right 
The whole group is selected, 
Beginning at the top or bottom of the table, hide all blank rows. Using the command key during the selection process will allow this to be done on the whole table at once or in groups of rows at one time; 36 of the 54 rows are hidden. 
the color may be replaced with white in the spreadsheet,
The other option is to unhide rows on the colored table, screengrab as usual after removing cell borders. Open in Gimp, crop to content, eliminate the cyan row by filling it with white. It was intended as a placeholder for the last row in the pattern, is not part of the final repeat.
The last image is in RGB mode once more, converted to BW indexed, scaled to 24 by 54, and exported as BMP or choose any other format ie png, etc. to suit your needs.
Each transfer design segment of the repeat is 6 rows in height and completed with 10 combined carriage passes. The lace carriage, LC, operates first, in a series of two passes at first, then followed by four, repeating the double sequence throughout. The mylar, card, or computer image, does not reflect the passes made by the knit carriage 
The design was not planned as continuous, but is easily amended to be so. Here an alternate version is shown, with 2 linear repeats on the left, and a single expanded repeat to its right 
As for that mylar repeat, this is an image of the shapes with the chart collapsed, eliminating blank rows between black pixels. 
In fabrics designed this way, using the image as drawn (left), or mirroring it horizontally, does not visually change the result. This does not hold true in more complex transfer lace.
2024:
Tiling the repeats to imagine the final knit presents the problem that results from working on a square grid and comparing the results to a knit, which usually produces a rectangular one. The representation for the linear patterns produced on the knit side of the piece cannot factor in some of the added distortions created by the stitch type used. I process my images in Pages or Numbers, depending on which document contains my most recent work and happens to be open. It is also possible to perform the final rescale in Gimp. Most knits approach a 4:3 ratio, with gauge variants in highly textured fabrics. To preserve a clean design, tile and save the original, screengrab the resulting image, load it in Gimp, and rescale. Repeat the motif for the same number in both height and width when tiling it. 
The colored versions before and after scaling, compared with the slip stitch swatch. 
It is possible to produce a rectangular grid to start with on which to draw in Gimp, but the larger canvas size occupies a significantly larger space on the screen, complicating the process. For small designs, however, that may be an option to give one the sense of aspect ratio for the design in the final knit ie in representational FI. To resize the grid in uneven proportions, the chain-link below the spacing values needs to be broken 
This repeat is designed for an electronic, requires color-reverse. Since it is 24 stitches wide and it may also be modified and used on a card. In this instance, the original marks for rows and stitches are single height. The image is processed, matching the original, rendered double-height, color reversed, and then alternate pairs of rows were color inverted to render the repeat used in the test swatch 
Once again, the possible change in scale is estimated. The repeat though only 24 stitches wide, is 92 rows high. On the left the repeat is shown as it appears on a square grid, to its right is the scaled 4:3 version, in a pixel count approximating the size of the swatch. It takes a bit of squinting to see the pattern more recognizable in the longer repeat in the larger tile 
The swatch was pressed, becoming wider than when first off the machine. It was knit using the slip stitch setting, could also be executed in tuck stitch, which would both widen and shorten the fabric and make the purl side more interesting. The software can provide a preview of the result far more quickly than knitting samples, but again, the previews are only approximations of the scale, and cannot show distortions to lines as one adds more texture.
and with a check tuck pattern that may change in aspect ratio considerably when knitted 
The proof of concept swatch, knit in tuck stitch, begins to show the distortion by the stitch formations, textures vs plain knit, easily seen at the top edge. The bind-off is around 2 gate pegs in order to allow enough stretch. 
Anyone familiar with either or both programs may find this a very quick way to visualize the scaling and moving of motifs within DIY designs and their possible outcomes prior to test knitting
In terms of positioning the carriage, a wire that is akin to that found on Passap strippers is on its underneath. In positioning the carriage on the beds, check visually that it is indeed lying between the gate pegs of both beds prior to attempting to travel with it to the opposite side 
For my test I used EON needles on the ribber, planned alternating selection for each new transfer. This could be done by selecting dashes and blank spots on needle tape ie. dash in the above photo, blank spaces below 
My first attempt at creating shapes includes a band at the bottom where the EON transfers as above were made, but every row. Simply bringing needles into work on the opposite bed creates an eyelet. They can be eliminated by sharing stitch “bumps” on the opposite bed, but for the moment they are a design feature. The texture created appears in the areas involved on both sides of the knit 
It is possible to transfer single needles at sides of shapes ie 
or whole rows, but the change lever needs to be set to position accordingly.
The enclosed punchcards: 
Transfers of stitch groups, whether by hand or using the accessories are made on rows where no needle preselection occurs on the main bed 
This series is a proof of concept for my approach to developing electronic cues
The original repeats were modified to include 2 blank rows between segments that allow for transfers between beds not hampered by needle preselection on the top bed. The motifs are color reversed, but not the blank rows between them. 
The knit carriage is set to select needles KC I or II, end needle selection does not matter. All needles on the top bed knit every stitch, every row, whether or not those design rows contain black pixels. No cam buttons are pushed in. Blank areas between black ones indicate the number of needles that actually need to pick up loops on the ribber to create shapes, filling in spaces between selected needles until an all-blank row is reached for making transfers. The chart on the far right illustrates a shape where the easiest method becomes one where stitches on the ribber are manually transferred to the top bed in order to reverse the shape and maintain every row preselection. The selected needle corresponding to the black square marked with the top of the red arrows is pushed back, the ribber stitch below is transferred onto it, the needle with the couples stitches is brought to E position, moving across the bed in proper locations prior to knitting the next row. 
In this repeat, the side vertical panels of ribbed stitches are added. The knit stitches on each side of them roll nicely to the purl side, creating what in some fabrics can actually be planned as an edging. 
My takeaway is to test the accessory with some patience, sort out the sweet spot for the ribber needles in relation to main bed ones in terms of handling transfers and yarn thickness, use colors that allow for easy recognition of proper stitch formation, keep good notes, and “go for it”.
In the first sample, equal thickness yarns were used, the colored yarn was a rayon slub with no stretch and slippery nature. 
The bottom of this test used a wool yarn of equal weight to the light color, which proved hard to knit. The red is a 2/48 cash-wooll 
Cast on for EN or EON rib. Transfer all the main bed stitches down to the ribber. Extra stitches can be cast on and transferred in addition to the planned width of the repeats to create a border on either side of the designs. During patterning there will be stitches in work on both beds at intervals, so the pitch needs to be set to H while knitting. When the top of the piece is reached, transfer all ribber stitches to the main bed and bind off.
If any stitches are pushed all the way back or in mixed alignment during transfers, 
Proof of concept: the bottom half is knit using the slip stitch setting, the top half in the tuck setting. The added texture on the tuck stitch purl side makes the fabric a more interesting, reversible one, and wider than its companion. 
For a different way of working with two-color initial images using only Gimp, see tips in 
Numbers processing to ready the repeat for final gimp editing: 
Getting back to clearer pattern results: when using electronics, it is possible to create far wider and taller repeats for download. The technique to achieve them uses the same process. That said, there are quicker ways to attain the final repeat illustrated in the 2024 posts on using Gimp color to alpha through the Layer> Transparency option or Colors> Color to Alpha.
the isolated repeat, double-length 
the color separation in progress
When knit, that white cell pair of rows break up the overall shapes and shifts the pattern in the top and bottom half 
The final adjusted repeat 
knit using the tuck stitch setting in both directions, KCI, first row left to right, leading with the dark color 
and here with the lighter color 
In progress, on the km 
the relaxed, 3D-ish view on the reverse 
why projects can take longer than planned 
The finished, relaxed scarf with pressed edges only, retaining the conical striped forms
The repeat knit double length, changing colors every 2 rows, becomes something quite different, with a sharp curl to the purl side 
with my color changer in this threading sequence throughout
where normally each color in each design row knits twice. Because selection occurs for pairs of rows, the first preselection row is from right to left. To decrease the backing rows, the ribber is set for birdseye. I prefer to have an end needle on each end on the ribber, keeping in mind that the total number of needles in use there needs to be even. The machine provides reminders as to which color should be knitting. My samples are knit using KCI on the top bed. Because the preselection happens twice, it is easy enough to knit in pattern from left to right, 
when the carriages have reached the right side, simply use a ribber comb to push all needles back to B. 
Speeding things up with color separation, beginning with the method that will have each color, each design row knitting twice. The repeat is 10 rows high, so it is expanded X6 to 10 by 60 rows. In the final result, the second row for each color in the separation is in turn erased. The red was added to make all 3 colors visible while working the separation, avoiding confusion with the white ground. The knittable result as usual is in a black and white png 
The img2track settings are for now for 2 color knitting, the prompts for the color changes are lost.
The ribber can also be set to knit every row, resulting in elongation on the knit side, while creating an interesting striper backing
Comparing this version to the birdseye backed one for repeat height 
Comparisons: HoP, pushing back needles to B, and color separation results. In the latter, the design is likely elongated in part due to a change in the distribution of thinner yarns to larger design areas with no tension adjustments 
The Ayab lettering as opposed to numbers move from right to left. The manual states that the color separation order is: white C, grey B, black A with their sequence = C (3), B (2), A(1). If the prompts for changing colors as given are followed it provides a very valuable in tracking them, but if out of habit one knits in the usual 1,2,3 sequence, the color placement occurs in an unexpected order and may result in errors. The on-screen letter prompt corresponding to the anticipated color change sometimes occurs with the knit carriage on the right, sometimes as it approaches the changer, and the size of the font was hard for me to see since the screen was not close enough for easy visibility.
If the png is copied from the post it is likely to appear in RGB mode and it will require conversion to 3 color bitmapped. Its grey color map entry is seen below 
The small file makes for a quick test of proper color selection for each of the three colors used 
Having some idea of stitch counts for each color in the design in the first few rows can help identify proper, planned color placement errors 
My first swatch using the heart of Pluto separation and a greyscale motif 
My tested color change sequence is #1, #2, #3 colors throughout, I disregarded the prompts for color changes at the bottom of the Ayab screen. Some things to ponder: in pieces that require color changes, starting with waste knitting in the same colors can help assess the best tension, whether each color will be picked up properly, and if the colors work well together. Looking at these 3 small tests, it appears that a choice should be made when casting on about using color 1 or 2 for the preselection and cast on rows. If the setting to slip is forgotten for the first move to the left, the color in the feeder will knit every stitch rather than a pattern selection. Always check settings when on the right, making certain lili buttons are set as well. This pattern does not contain 3 colors on every row. In addition to that, when working DBJ with other color separations one is likely used to seeing knit bed needle selections on every row. That is not true here, is a function of the technique, not a patterning error. On rows that have colors missing, when that color is in use, the main bed slips, the ribber works every other needle, first in one direction, then the other, adding to the row count on the purl side of the knit. 
The mess at the bottom was due to the green yarn getting caught on the needle bed and not knitting the necessary stitches on the ribber, so dropped stitches were formed 
The assumption is that if the C, B, A rotation and prompts are to be followed, the middle color 2 can stay in place, and the placement of 1 and 3 can be exchanged.
