Weighted color averaging for reagents

Created by: 9600bauds

Continuation of #4392 Turns out doing this was a LOT simpler than I had thought it would be. Shouldn't even be any slower than we had before.

Diluting coffee and OJ into 20u Milk http://puu.sh/hKN4W/201db567af.webm

Promis good cryomix vaery healthy