iSight cameras are fun toys and useful tools. I’ve messed around with the built-in Photo Booth application taking all kinds of dumb pictures (none posted here, sorry), and there are various applications available that will trick out your iSight for all kind of silliness.
I was recently demoing various cataloging software (Delicious Library, Books, and Bookpedia) to try out iSight barcode scanning. It works as well as advertised with Delicious Library (really well, in fact — that Wil Shipley is a smart feller), and some of the time in the others (which share the same code-scanning library). That was good to find out, but after I was done messing around, I found that my iSight was permanently switched to black and white. I could get any of the color effects in Photo Booth to reset it.
Tonight I inadvertently found a way to fix it. The solution is to get some software that lets you change the iSight saturation setting. I used ProScope HR, but there are other options like iGlasses or iVeZeen that will do this for you. ProScope has the virtue of being free, which is nice for this purpose. ProScope HR is designed for use with their ProScope microscopes (which look cool, by the way), but will also take still pictures, video, and time-lapse video with an iSight as well. I haven’t played the time lapse video feature, but I could imagine that being a great way to waste time.
To fix your iSight, open ProScope HR, and click Image Adjustments. On mine, the saturation slider was all the way to the left, at 0%. Crank it up as far as you want, click OK, and everything’s back to normal.