Large RGB Cube/Panel

ok, for some reason I can’t seem to find what I’m looking for. I swear they exists but maybe I am wrong. Here’s what I need: I want a large RGB panel or cube which I can change the color of via USB/Microcontroller. I’ve seen several LED panels but they aren’t diffused like I want. I want the color to flow evenly(ie, the entire cube/panel be the same color). Does such thing exist for sale? I found a instructable that kinda has what I want: http://www.instructables.com/id/SAPNIFEFJI8VZPO/ but I was hoping the forum has better ideas.

sort of like these?

http://www.ambientdevices.com/cat/orb/orborder.html

or the weather beacon down the page at this link:

http://www.ambientdevices.com/cat/products.html