You may also want to check Colorpic
http://www.iconico.com/colorpic/Version 4 is now available, with the following features: • Easily pick any color from the screen
• Totally 100% Free!
• No popup adverts or spyware, it really is free
• Colors shown in hex and decimal
• Adjust Hue, Saturation, Value, Red, Green and Blue values
• Cyan, Magenta, Yellow and Black percentages shown
• Easy to use with any other program
• Resizable magnification area
• Overlay a grid for quick colorpicker alignment
• Use arrow keys to nudge mouse pointer
• Save multiple palettes of colors automatically
• WebSafe Colors and names displayed
• Snap to nearest WebSafe color
• Point sample, 3x3 or 5x5 pixel color sampling
• Adjust color with four advanced color mixers
• Edit colorpicker values after selection easily
• Easy to use collapsible sections
• Works with Firefox, Internet Explorer, Photoshop and any other application