Free color picker software
Sometimes you may want to match a color in your design or configuration but it is very hard to figure out what is the color code. With ColorPic, you can easily retrieve color codes by pointing your mouse arrow to anywhere on your monitor.

Another possibility is Instant EyeDropper.
Please see http://tech.islesv.net/2008/04/how-to-know-rgb-code-of-pixel-on-screen.html