I have 1 red and 1 yellow on my coin door reject buttons. It gives a nice orange glow to them.
Ahhhhh... interesting. So each red reject has a single red and a single yellow LED behind it?
You got any pics?
Thanks
Yeah! Sure.... Here you go...

They sit on a little bit of strip board that goes straight into the original lamp holder sockets.
I don't have a pic of them lit up, but you can see how they go in and two Ultra Bright LEDs is more than enough output. At least as bright as the original incandessant lamps.
If you use two reds, then they are VERY red.. The red and yellow together makes a great orange colour, that almost mimics the colour you get from small Neon lamps.
Best Regards,
Julian (Fozzy The Bear)