I playing with the thought of building a LED-coffeetable. I would like it to have a black top when it's not "on". How does color-leds shine through on translucent black acrylic?
It's sort of a purple-ish colour (if you use white light). Other colours probably won't suffer from any noticeable contamination though. Not sure if you can see it here, but I used 3mm dark smoked acrylic, and the white LEDs inside the case have a slight purple hue: I later swapped these for red LEDs and I can't see any purple at all.
I work for a sign manufacturer and we light all kinds of acrylic. My experience has been that you can never know for sure until you actually have the acrylic on hand and do a light test. It never seems to light quite the way you think it will. One way that we correct when the acrylic does not light in the exact shade we want is to apply a thin film of colored (or smoked / opaque / etc ) vinyl to the inside surface of the acrylic. using different colors of vinyl and led combos, we can usually hit the money after some experimentation.
