A light theme using only pure colors (#000000, #FF0000, #00FF00, #0000FF,
#FFFF00, #FF00FF, #00FFFF, #FFFFFF) designed for e-ink color monitors based
on the Kaleido 3 panel (e.g. Dasung Paperlike 13K color).  The palette avoids
dithering by staying within colors each RGB channel can render cleanly.