After seeing Dr_Mabuse's really sleek and sharp dice tower, I was inspired to try to make one too:
I made the tray black because I like how the dice jump into view. I used foam board and Gilad Yarnitzky's design. I stuck black glossy card stock on the outside to give it a clean look. I sprayed a couple of coats of low odour acrylic spray to protect it and make the black even blacker.
I used a wooden skewer as a pin to make the tower attachable/detachable:
Attaching the tray makes it easier to move the tower around during a game if you need to.