Although knitting designs in more than 2 colors is associated with issues in maintaining aspect ratio and discussing the performance of specific color separations, PNGs planned in multiple colors can serve as a paint-by-numbers start and eventually be reduced to BW.
In DIY begin with a small repeat for pattern repeat and knitting tests to determine preferred techniques and final appearance
18X16
the pattern movement determines the single repeat size
48X48
Familiarity with software aids in developing baseline custom charts that are useful in planning DIY designs in linear, diagonal, or rotated aspects.
Chosen motifs can be added and distributed based on personal preferences.
The first charted grid for later motif placements begins here with a 40X40 repeat
also isolated to 80X80
Working with seasonal motifs 
after removing a few more pixels
creating blank negative spaces or areas for other motif additions 
varying the frames for each segment,
32X32
with added blank rows 32X40
adjusting foundation grid repeat, 52X52 
a published repeat with source designs 
isolate and add motifs, erase or change pixel colors to suit, choose final segment(s) to place in the overall design
color to alpha 
isolate the smallest repeat, 52X52
Working with horizontal repeats: the appearance at this scale of a third color is an illusion, the PNGs are BW
38X52 with half the height color reversed 
adjusted to 36X50
When intending to explore colorways matching available yarns in fair isle bands, work with expanded palettes/RGB mode 
a cousin in BW began with 36X126 
steps in editing 
removing/adding a few more bothersome (to me) pixels 
