I've been wrestling with the Coloramp converter node while creating a separate shader. I'm using this shader to create procedural freckles that can allow me to adjust size, position, shape and color of the freckles so I can reuse it in a variety of characters/creatures (or more). The problem is, I need one of the colors to be an Alpha channel, just clear. The shader is applied to a vertex group that lets me control placement. The shader block feeds into the mix of the rest of the skin but I have blocked it out separate to make it easier to get to find and adjust for the situation:
When I originally set it up, it laid it down great and let me make any adjustments, the problem was, the second color was white and showed on the vertex painted area. I tried everything I could think of to change the white to an alpha but had wacked results. So, I changed the second color to match the blush on the cheeks, which works pretty well in this one case but is not a solution, there will be times, and characters, where that would not work well. Here's the coloramp second color white, and another blush:
It would be great to have that as a separate shader that can be saved to the library but, I need that alpha channel on it in these cases. Any suggestions?