Overlaying nodes in shader graph

Does anyone know of a way to overlay nodes in shader graph without losing colours?

If I have the following:


I'd like to get the end result:



I've tried nodes like "Add" (loses the colours as they get added) and "Blend" (doesn't seem to be a filter that does this) to no avail. What I'd like is one that allows me to overlay one over the other and ignore any pure black (or give me a threshold option)

Thanks!

 

I'm assuming the nodes just to the left are greyscale masks and individual color values. Funny enough the solution is nearly the same as your other thread. Use a Lerp (or rather a few of them).

Use the red as is, then use a lerp node to blend from the red (A) to a green color (B) using the greyscale value as the mask (T). Then again to purple.

 

That's great, thanks! I didn't quite get how to lerp in the other thread.

I've left my finished graph below for anyone else that wants to see:

 

Use Smoothstep instead of Step.

 

Ah, that works great - thanks!