AdesClrPicker is a very user-friendly, small yet powerful color picker program.
It allows you to capture colors anywhere on the screen with a single click of the mouse and output it in HTML, RGB, VB, Delphi or C++ color codes.

Floating panel makes it easy to pick colors from screen. It has the most frequently used buttons on it. It stays on top of all windows.

Color library allows you to save colors in a text file. Or export them as an image (gif, jpg, png) or export it as a Photoshop swatch file.