I made a blaster using an airsoft tracer unit. It used glow bbs, and they get charged as they exit and look like tracers. You can get other color bbs too, so's to mimic other blaster bolts.
Then I tried scaling it up. I got a nerf zeus, and some glow balls. The intent was to either charge the balls as they exited or charge them in the magazine, since it's clear. But the balls were terrible, they didn't take a charge and looked super dim. I eventually just gave the whole set up to my friend and his kids, that was my good deed for the day.