mos.24bit.std.cmap
The colour map that mos.24bit.dstyle indexes into. One line per colour:
# R G B idx color-name
255 255 255 0 background_gray
220 95 95 1 poly_red
66 213 66 2 diff_green
RGB is 0–255, idx is the number a display style refers to, and the name is a comment for humans.
Change a colour here and every layer drawn in that style changes; change a style in the .dstyle file to move one layer onto a different colour.