Here is my setup
*one directional emitter in neg y direction with speed of 2.0 & speed random=0.9
*creation expression in rgbPP as rgbPP=sphrand(2);
*lifespan 4 ever
*bounce=.25,friction=0
*color of particle rand only @ birth bcz of creation expression
And my doubt is
*how to change color of per particle @ every collision to surface (color will change rand for each particle @ the time of collision)
*and after change in color the value of rgbPP remain same till next collision for that particle.

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