stain, dye, paint, marble, splash, woad
color, discolor [heh]
and some you may not have: infuscate (darken), scumble (soften), countershade (lighten/darken), embrown (tan), rubrify (redden)

and thinking of redden, blacken, etc. vs. blue, green, brown and so forth suggests that these verbs followed the two paths that Nicholas wrote about with verbs like quicken vs. quiet. and then we have embrown and empurple.