I also don't think colossus are paintable though I haven't tried. I'll test some theories and report back. (If anyone wants to help, please do!)
== Removing some notes from the main side ==
* Black dye has little effect on a light source (No black light) and only dims the light a little. And it doesn`t dim light sources around it.
** Testing reveals ''An excellent black dye (R=12 B=12 G=13) on a 45ql lantern light looks the same as a 40ql no dye lantern and a little dimmer than a 43ql white dyed lantern.''
* A 2.5ql rare copper lump produced a 3.5ql dye