If it's truly black and white use an Unmuly effect to just keep the black areas and white will be matted out. Then go you can tint the areas that are visible. You can set the blend mode back to normal if that works for the rest of your comp
Now that I'm back to work from this GTX fiasco, I have a simple question.
I'm using an image that is black and white. So, I have this little design in black with a white background. Naturally, if I set the mode to Multiply, I get just the black like I want. Now, if I want to change the color of the the black using tint or CC Toner or something, it then brings back some masks and essentially nullifies the multiply effect.
How can I easily change my color? It is precomped already.