Fake SSS with depth mask

I have an idea of post process SSS that is mainly based on color information and depth.

1. Here's original look.


2. Lower down the brightness, this can affect the SSS position.


3. Apply gaussian blur, this can simulate the depth of the skin.

4. Apply gradient map. the skin color should be adjustable while the greys are static.

The gradient looks like this, but should be adjustable so it adjusts the tightness / finetune the depth of the skin.


5. Mask the effect using depth map.


6. Apply the effect using Overlay blending.


I have no knowledge in making a shader so if someone could teach me the ropes, or at least make this shader so I can look it as an example, that'd be great.