When we need to get exact color of some pixel on our screen, we copy screen content into clipboard, paste this image into some image editor, and use some tool of this editor to get the pixel color. Long way... Screen Beagle's Dropper do it with easy. Just activate it, move mouse cursor over the screen, and information window will show the color itself, color in RGB, RGB Hex, HSB, CMY, CMYK and in HTML format. Click the target pixel to select the pixel, then click any value in information window to copy this value to clipboard, if you need it. Next click on the screen will release the selection.
Activation: tray icon menu, dropper tray icon (customizable) or dropper hot key (customizable).
More details: http://greatis.com/utilities/screenbeagle/dropper.html