Getting the areas of multiple intersecting Trigger Colliders.

I'm working on a project about mixing colored lights together. To do that, I'm using mesh colliders as triggers. I've been trying to figure out a way to get the area or group of points where the colliders intersect so I could possibly use them as an object to create interesting events such as changing their physics or using particle effects.

What I basically want to do is:

If Light1 is colliding with Light2, 

        Get all points where they are colliding with each other

        Turn the group of points into a mesh collider trigger

        Give that mesh collider trigger a script for when something else enters it

In other words, if you have a Venn diagram, I want to just get the part where both shapes are intersecting and turn that into a usable shape.
So far, the closest answer I've found is the use of plane structs, but I'm not sure how to implement it using my limited coding skills. This is mostly for the purpose of rapid prototyping.

Any help would be greatly appreciated.