Here's some more information on SMD LEDs. First, they are small. really really small. And impossible to tell apart regarding the color. To sort out the colors I received in a package, I put together this LED tester. It's got two servo pins to pick up and power the LED, and a 120 ohm resistor so that it can be powered by a 1S lipo. So far it's working well, and the tips don't touch when the tweezer is squeezed together. Everything's assembled with shrink tube. Be careful, because if the LED slips (as I learned by hard experience) it will shoot out of the grip of the pins and be long gone.
Here's the resistor values I'm using, based on the LED data card from the ebay vendor. Two nice resistance calculators are
here (with color codes) and
here (with parallel and series calculations).
