ColorMania is a extended colorpicker with an eyedropper component and a screen magnifier.
ColorMania lets you easily select and modify colors. It's the ideal tool for website and application developers. You can pick colors from anywhere on your screen and intereactively change the RGB and HSV values.

ColorMania Features
Interactively change RGB and HSV values
Eyedropper / Screen Magnifier
Color display in different formats
Intuitive Interface, Uninstall support