Multi color tint shader?

[NotGaylien]

If i have clothing models with lets say sleeves one colour and the base torso/chest part a different colour, the only ways for me to allow colouring of both is to use 2 materials (not good when people can wear like 6+ pieces of clothing, and lets say 10 people were doing that i would have 120 draw calls instead of 60)

If possible could we get a shader which allows for a mask (like R, G, B channels for the mask to define what part of the material should take what color tint) and multiple colour tint options, unless there already is a way that i have miss.

well with that i would want to mess with the individual color tint for each of the masked parts in code so idk if its feasible?