I Have heard o f people spray painting it black with a latex fusion something paint. I've seen the paint on other applications underwater and they last for a good while. Just sayin if someone already has eggcrate you could do that aswell.
Lowes also carries the 2' x 4' white eggcrate which is just replacement grid for light fixtures. It is by the flourescent fixtures in both stores and they also have it back by the lay-in ceiling materials. I have not checked but it may be available at ACE hardware http://www.homedepot.com/p/Plaskolite-4-ft-x-2-ft-Suspended-Light-Ceiling-Panel-1199233A/202025149
