OK first off you're not all going colorblind. On the first image (A) I am not sure that there is a number there. If there is it is very subtile. The image comes from a discussion on color blindness that was refered to on a thread on the poser forum. I found on that thread that there are many artists with some sort of color perception problems. Here is a link to a related site which might be useful and the article on colorblindness from which the test pattern comes from. The images (B) and (C) come from a short discussion on .bum maps I had with MartinC . Thanks for participating. There really is no reason that you should see either one as raised or lowered, but the common perception is that one appears raised and the other lowered, or both raised or both lowered. To visually communicate effectively it may not be important, but then you never know. again thank you, - TJ Zhann, As the circle appears to be perfectly round, I can't trick my eye into believing that either color procedes the other. if I were to base it on color I would say the red would be closer, but my eye does not believe that.