ColorPix is described as 'useful little color picker that grabs the pixel under your mouse and transforms it into a number of different color formats' and is an app in the Photos & Graphics category. There are more than 50 alternatives to ColorPix for a variety of platforms, including Windows, Mac, Online / Web-based, Linux and Android. The best alternative is Just Color Picker, which is free. Other great apps like ColorPix are gpick (Free, Open Source), Instant Eyedropper (Free, Open Source), gcolor2 (Free, Open Source) and Sip (Paid).
ColorFan is a color picker application that lets you select from a fan like interface. iPad users, check out ColorFan HD The selected color is presented along with some related colors that you can finger through.