Okay, I have a body hair texture map, white hair on black background.

The reason it's white, is because I want to use it as an overlay/second skin and change the color of the thing.

I did this before, and I can't for the heck of me remember how I did it. Nothing I do has any effect on the color, it stays white, regardless.

I know I'm doing it wrong, but I'm losing the will to live lol.

If anyone has any suggestions, please let me know. :)

Use any black/white map as a mask by connecting the mask to a Blender, Blending input.

Then you put the two things you want it to choose between into the Value_1 and Value_2. They can be colors, other maps, whatever.

White on Black is normally the Transparency Map...

What is the Material Room Setup with the Image Map? (Screen Shot)

My hair map is from Apollo, and it is black on white. Actually it is gray on white. Anyway, I inverted it using Math:Subtract to make the hairs lighter than the black where skin should be free of hair.

Plug the hair map into the Blender Blending value. Put the skin color in Value_1 (I used an the Apollo color map) and then hair color in Value_2 (I used a fixed color - brown).

The Blending value can be any number you want, and the higher it is, the more the hairs are visible. You can see a render and some previous renders at different blending values.