Just don't forget to reduce the colors some more, ideally not more
than hundred. Otherwise people running on 8 bit displays will run
out. When reducing colors, avoid dithering, it looks bad on icons
this small. And use the same palette as for the other icons also,
so the sum of colors Emacs uses doesn't increase (it is on the limit
for 8 bit displays already).
Did you do the conversion manually, or did you use some special tool
for it? Actually, this is a stupid question since you probably did
not use pencil and paper. So what tool did you use, and how?