My Character (can be anything you want including triggers) https://i.imgur.com/smUvRSm.png
The Sphere BP https://i.imgur.com/fPRLVUD.png
In my case I assigned the ID directly via Viewport but you can do it via Code to or during the Spawning Process. Thats really up to you https://i.imgur.com/5DUL6uO.png
And the Result 1 & 2 give a fixed color and 3 is randomly choosing a color between yellow and Purple alternating between groups. Screen capture - 77d5af894648da9bd97d41af62320dd6 - Gyazo
In the Game Mode theres just the Dispatcher and the Material just has that Named Color Parameter. Thats it =)