You cannot "add colour" in a Butter/Mojave. Fire, when added to a BluEL will, as I mentioned above, be more likely to push you to a whiter snake without the dorsal stripe. Cinny, does not seem to do much one way or the other when added to a BluEL.
In "dirty" BluELs (SuperPhantoms, Crystals, SuperMojaves, etc.) you can sometimes tweak pigmentation but it is almost always toward further lightening them. I cannot think of a "dirty" combo that I have seen where it was made darker...