what is the brightest RGB combination of leds that won't need a heat sync?

I need to fit a red green and blue led on a <1inch diameter circle. It has to be EXTREMELY bright.
BUT I can't give it a heat sync.

Do I have any options whatsoever? It needs to be RGB. And REALLY friggin bright.

It will basically go inside a dead glowstick.

I really wanted to use high power leds, but this is looking like it will get to hot... Is there any way to almost get as bright as a high power led?

What are my options?? Please help me! I've spent all day today looking online.

aelias366 years ago
You could probably be able to use rectangular-shaped LEDs. You cram more into that space with LEDs that fit together nicely, rather than just leaving a space between them like regular LEDs. Remember that this means that there's no lens, so if you want the beam to be directional, you may need to wrap the sides with aluminum tape and stick a lens, (super-thin plastic Fresnel lens, perhaps?) on the front.