I was thinking about the Street Hockey idea and the lighted tape measures. Check out this glow in the dark Street Hockey Ball:
Maybe during the Autonomous Period or the End Game the playing field lights go out and the glowing balls are randomly dispensed onto the field? The goal(s) could be ringed in lights
The robot flashing lights and "bling" lights might be distracting, but there could be a rule about the colors of lights you're allowed to have on your bot.