Change the material of ONLY a specific body part of an avatar

Hello,

I am currently trying to develop a demo where certain parts of an avatar (such as the left arm) will change colors in certain scripted situations. I did a prototype of this, where I just made a simple, stick-figure like, figure using separate game objects. I developed a material that could switch between two sharers when triggered, which is exactly what I was going for. However, for our main demo, we want to use an avatar made in Adobe Fuse, which has all body parts as a single bodymat mesh, so my old technique doesn't work. Is there any way to change the colors/material of only certain parts of a mesh?