ColorPad is described as 'A very lighweight yet powerful color picking tool. Skin support' and is an app in the Photos & Graphics category. There are more than 25 alternatives to ColorPad for a variety of platforms, including Windows, Mac, Online / Web-based, Linux and iPhone. The best alternative is Just Color Picker, which is free. Other great apps like ColorPad are Instant Eyedropper (Free, Open Source), gcolor2 (Free, Open Source), Sip (Paid) and Colora (Free, Open Source).
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.