After much pondering, I finally decied to color Limit's mane and tail, shading gradually from white roots to deep blue tips. (A variant
the_vulture suggested, that I'd been considering after posting the poll). I also tied up his mane to make the mane less overwhelming on the right side. He looks pretty similar from the left side, but on the right the change is pronounced. I also varnished him to protect the paint job, so he's glossy now, which is more glaring in some of these photos than it is in person.
More pictures here!