Color Pickers

Abitom's Color Wheel Expert
A Windows color picker utility to help designers create harmonious color scheme with the color wheel. [Windows 95/98/Me/NT/2000]
http://www.abitom.com/

Color Cop
A free multi-featured color picking tool. Has a eyedropper, magnifier, 3x3/5x5 average sampling, complementary color generation and variable magnification levels.
http://datastic.com/tools/colorcop/features.php

Color Picker Pro
Pick one or several colors anywhere on the screen with a single mouse click. It features 2 capture modes, interactive zoom tool, 20+ color formats, and 10+ color spaces.
http://www.diplodock.com/Products/ColorPicker/default.asp

Color Schemer
Software to generates matching color schemes at the click of a button, online version available.
http://www.colorschemer.com/

Color Wheel Pro
Color scheme creation program that uses an interactive color wheel and allows to preview color schemes on real-world examples. [Windows 98/Me/NT/2000/XP]
http://www.color-wheel-pro.com/

ColorImpact - Interactive Color Wheel
Interactive tool for designing harmonious color schemes. Aimed at professional multimedia and web designers, the program includes features to integrate with graphic programs and HTML editors. [Windows 98/2000/XP]
http://www.tigercolor.com/

ColorShade
Creates matching harmonious color schemes. Includes web, scrollbar, and vector image preview, and palette creator.
http://www.colorshade.com

GAX Professional v2.2
Pick colors from every part of the screen; GAX automatically detects the palette of various windows on the screen, therefor sampling the color with 100% accuracy. Included are a screen ruler and a screen-capturing tool with a variety of ways to capture parts from the screen or the entire screen.
http://www.dolphiq-sd.com/

Get Color Sf
Free color picker with a magnifier control that will magnify any part of the screen (levels of 1x-20x).
http://getcolorsf.sourceforge.net/

Iconico - Color Picker
Color picker for high-resolution monitors, has a magnifier attached. The magnifier is controlled from the keyboard, and grab up to eight colors at once. [Windows NT/98/95/2000]
http://www.iconico.com/colorpic/

Nattyware - Pixie
Utility designed especially to fit the needs of Webmasters and Designers. A color picker includes a mouse tracker. Run it, simply point to a color and it will tell the hex, RGB, HTML, CMYK and HSV values of that color.
http://www.nattyware.com/pixie.html

Super Color Picker
Automatically copy color code to clipboard, and show color codes in RGB, HSL, HTML, Delphi, C++ and VB formats.
http://www.esier.com

Technical Vision
Pick colors from anywhere on screen with a single mouse click or a key press. Shows the color in a variety of ways including RGB and HSL pairs, Delphi, C++ or HTML constants. Copy any code to clipboard. Minimize to SysTray when unused.
http://www.techvision.ro/

WhatColor - A PC Tool For Colorblind People
Software designed for those people with partial or total color blindness. It identifies a color of the pixel on the screen of the PC. It tells not only RGB values, but also the name of the color of the point.
http://www.hikarun.com/e/