Each 6 digit corner color number is a R-G-B color triplet
with two digits (hex) indicating the intensity (00-none to FF-full)
of each of the three colors. For example:
FF0000 = red
00FF00 = green
0000FF = blue
000000 = black (all intensities off)
FFFFFF = white (all intensities on full)
FFFF00 = yellow
Note: to be compatible with displays limited to 256 colors
use only combinations of 00 33 66 99 CC and FF in your colors.