Quoted from Snux:The Batman ramps look like green plastic from all the pictures I can see. I found (but never tried) that you can dye PETG.
» YouTube video
http://www.tk560.com/phpBB2/viewtopic.php?p=3459
Looks kinda fiddly, but might be worth experimenting on some scrap pieces if you have any.
God knows I have plenty of scraps! I think I'll try it sooner than later to see how it looks as well as how it will hold up. Maybe place one outside in the sun...wait...I live in Seattle so I won't see the sun for a while. Sounds like a good secondary use for my turkey fryer!