In the new site beta I don't see any dimming feature. Many flash game sites have this, and it would be especially useful here because the background is bright white ... this causes me eye strain.
If you find a certain background too bright, you can always edit the brightness on your computer itself a bit lower. On my computer all you have to do is click 'Fn' and the the left and right arrow keys to go up and down. Same with the sound but the sound it controllable with the up and down arrow keys to change the volume. You may have to go in a brightness editor which can be found in the bottom right (PC) top right (MAC) of your screen. It is programmed into your computer so it should definitely be there. You just have to look a bit.
Hopefully you won't have too much trouble with that and won't have many problems. I don't realize why you mentioned that the background was white because there is no background that is white. If you are seeing a completely white background, then this could be the cause of your current anti-virus program that you are using. You could disable it, but this would make your computer much more vulnerable to threats.
