Quote - You don't need to make a color map. You can use the white-on-black veins map connect to a Blender node's blending input. Then connect the original color to both color inputs of the Blender, only make the first color chip white, and the second one blue. Adjust the strength by setting the blending value.

 

honestly I could do that with a white map with black veins but not as you say (black background and white veins), when you have a minute I would like that you will tell me how to connect the nodes to make the color map from bump without having to create a new color map in photoshop

thanks in advance