It's a cop out, but it depends on what's better for your story.
Some of the best horror comics I've read are manga, so I dig black and white a lot. But I also read one of two color comics that are the shit. Have you ever read ''Wytches''? It has this awesome color pallet, desaturated colors with spots of really shiny stuff.

Dawg had a great point with her post. The Shining is a great example. But I'll add that, although desaturating is more normal, really bright colors can be creepy too.
''Cries and Whispers'', by Ingmar Bergman, while not a horror movie, is one of the most uncomfortable, creepy movies I've ever seen, and he works with this hot overwhelming red.
It's great stuff.
It's all tools, it's about how you apply them.
As a bonus: Have you guys read Zashiki Onna?
Hot damn it's the creepiest shit!!!