Single post in Proposal to Rename Albino and Melanistic Pokemon

How about Inky for Melanistics? Ink is black (but not pitch black I'd say) and a lot of Melans are darker tones of colors than their normals. There's also the prefix Melano, which means black or very dark, but not completely black. It still stays with "melan" as well. Crepuscle is a "fancy word for twilight" and Gloam is a verb meaning "to grow darker." Caliginous also means "misty" or "dark" like vampirecatboy said.