sanjac1620 sells 1/4" sheets of glacier white and cameo white on eBay. I have been using the first one, but cameo is almost as white. If you use an incandescent light, the color comes from the light. sanjac's store:
http://search.ebay.com/_W0QQsassZsanjac1620QQhtZ-1
You can also order samples from Corian as well as the others (Avonite, Hi-Macs), but these are almost always 1/2". I have split them with a band saw to make 2 pcs.
You look at the machined side. The image looking from the back side is not sharp.