Twenty Eleven Gallery Dull Thumbnails

I am building a gallery page with my photographs. The thumbnails, or even small images that make up the gallery post page are all dull. The colors are dulled. But when I click on the image, the linked image shows up in full color.

Anyone have any idea why that might be happening?

Here is the temporary test page:

http://chesswork.com/coaching/chess-edwards-photo-gallery/