I need to fit an LED that can light up in a space no larger than 4mm x 4mm x 4mm (H, W, D). If it can receive some sort of power signal from a mat or transmitter underneath, that would be fine... as long as the LED itself DOES NOT require touching to that mat to turn on.
The only function needed on these LEDs is to light up... possibly by touching a side of the plastic it's enclosed inside of. Otherwise, no color changing or other functions. Will want multiple colors of LEDs to be able to be used in the project (i.e., white, blue, purple, red, etc). The LEDs should be able to light up to a foot or so above or away from the primary source.