Changing Color on PhysX Interparticle Collision

[stusic]

Thanks for helping me, I really appreciate it and it's super helpful while I'm learning.

I looked at what you said, along with taking a hard look at my events and thought it would make sense to move the Property Test to near the end, just before the Mesh and Display operators. I thought this made sense because it can step through all the collisions/forces/etc and only needs test the property before it displays it. Please correct me if I'm wrong!

Anyways, I feel like I have it set up (mostly) correct now, but... still doesn't change the material.

I have the search info enabled, so I can see it should register the neighbor. I created a multi-material with grey in ID1 and red in ID2 and have it assigned in the beginning Instance Material. I've disabled the second Property Test because I thought it would be redundant (it's if it didn't pass the first test, then it would be grey).

Would you mind taking one more look and see what I'm not doing right?

Thanks a heap

-stu

Edited to add the file if it helps.    
  PropertyTest_ChangeColor.max (Size: 3.29 MB / Downloads: 117)