ColorJack: Sphere (Color Theory Visualizer)

Create color palettes based on color theory. ColorJack shares a visual tool to help you pick out the right colors for your project. Great tool!

[ws] Color Scheme Generator 2

Color wheel for picking website color schemes. Generates excellent color schemes in Web-Safe hues and according to different color wheel complimentary theories.

ColorSchemer – Online Color Scheme Generator

Given a hexadecimal color, generate a color theme based upon that color. A useful site for getting complimentary colors and keeping everything in the same color scheme.

ColorBlender.com | Your free online color matching toolbox

Online tool for color matching and palette design. 6-color matching palette.

4096 Color Wheel Version 2.1

Color wheel that allows you to select the color you want to use for a web page. It then returns to you the color code hexadecimal equivalent. Web-Safe, web-smart, unsafe colors.

Online color chart picker – web safe, smart and HEX color codes

Online color chart provides HTML color codes (Hexadecimal, Web-Smart and Web-Safe) in very accessible format.

ColorPicker.com : Quick Online Color Picker Tool

Simple and easy online color picker.

Color Picker

Photoshop-like JavaScript Color Picker .This color picker mimics Photoshop color picker by layering transparent images.

ColorPicker 3.1

Color picker with auto-test page. Sample page and CSS generator.

slayeroffice | tools | color palette creator v1.6.1

It will create 10 shades of the base color, located top-left, at varying degrees of opacity.

Color Fields Colr Pickr

Flash based color tool. Find Flickr photos that correspond to a given color.

colr.org

A nifty site that will generate color lists from images or web sites. Color Scheme extractor.

kuler

kuler from Adobe Labs. Quickly create harmonious color themes online. Explore, create and share color themes.

COLOURlovers :: Color Trends + Palettes

COLOURlovers™ is a resource that monitors and influences color
trends. COLOURlovers gives the people who use color – whether for
ad campaigns, product design, or in architectural specification -
a place to check out a world of color, compare color palettes, submit
news and comments, and read color related articles and interviews

Yahoo! UI Library: Color Picker Control

The Color Picker Control provides a rich visual interface for color selection. The interaction is a familiar one from the desktop paradigm: Color range and saturation are adjusted via sliders while the technical details of the current color are displayed in RGB, hex, and/or HSV formats.