Optifine has a way to change the resource loading screen colors in color.properties: https://github.com/sp614x/optifine/blob/master/OptiFineDoc/doc/color.properties#L275
I really like this property in my resource packs, but sadly colormatic doesn't have this (and so does mcpatcher's version). I think this is a great idea, but that's my opinion. Please give it a thought.

Example:

Mojang's brand guidelines preclude using other color schemes on their loading screen.