Changing Color on PhysX Interparticle Collision

[stusic]

Hi All,

I feel like this should be simple, but I'm new to Tyflow and tend to get held up as I learn, so please bear with me

I'm trying to change the material of a particle if it gets too close to another particle, then return to it's starting material when the neighboring particle leaves the radius.

I see there's a Property Test type "Neighbor count" that includes "Neighbors within particle's radius", but I'm not sure how to get it to work. I thought maybe that test would be avaialble in the filterss section of the Instane Material operator, but alas, it is not.

So how do I test it for neighbors, change its material, then continue with the flow?

I appreciate any help, I've included screenshots for reference. Please don't laugh at my flows, lol.