NCloth real time distortion map to drive RGB


I am starting with a cube. The idea is to change vertex color based on the variation from current position and its original position.

I need some advice. I tried to create an expression, but it won’t update the color vertex on each frame.
I was wondering if I can use some attribute from outputCloth node capable to generate some “distortion map” - meaning vertices far from their original position will be brighter than those vertices preserved in position.

for example: comparing nClothShape node Output Mesh and Output Start Mesh. If I can access vtx information on a frame base from these attributes I could calculate a distortion map,