Just some specfic links from One Sumus' post above:
http://www.ficml.org/jemimap/...wheel.html
Move around the color wheel and find out which hex codes for that color are “web-safe”, “web-smart”, and “unsafe”.
http://gmazzocato.altervista..../wheel.php
An interactive color wheel that tells you which foreground and background colors will work best together.
http://meyerweb.com/eric/tool...lor-blend/
Enter two CSS color values and it will show you the mid value for both.
http://www.colorsontheweb.com...wizard.asp
Enter a base color, and receive matching colors, hue, saturation and tint and shade variations.

Here are some more color-resources: http://mashable.com/2007/09/2...s-toolbox/

can't believe no one has mentioned the original site adobe jacked their kuler idea from: http://www.colourlovers.com

I use Color Impact 3 from Tiger Color most often in my work. www.tigercolor.com

Color impact is relatively inexpensive ($50 or so US?) and nice functioning software. It provides all kinds of options for color selection and tweaking. You can input colors from their RGB, CMYK etc. codes or from a chroma display. It has options for color blending (from increments of 2 or so to over 200) starting with a beginning and end color and with options to explore a direct linear route between them as well as circular ones in a couple of directions. It has great color harmony, color formulae (light to dark, saturation, etc.), and all sorts of test patterns to see what choices might look like applied to different scenarios (web design, fashion, packaging, typography, signage, etc.). You can filter to work with only web safe colors, explore cooling or warm selections (to simulate lighting, etc.) and even see what choices might look like to the color blind (nice if asked to design things for safety applications).

I should also mention Huey and Huey Pro ($80? or so from Amazon) by Pantone. While there are other monitor calibration devices out there these two from Pantone are small (about the size of a short cigar) and seem accurate to me. I carry one with my laptop for client presentations and even for balancing color when using a projector. Of course I use it on my desktop system too.

Huey attaches to the front of your screen and a USB port. It reads the intensity and color of the light in the room and adjust the monitor accordingly so that the screen colors are close to hand held reflective color things. I would make sure you do the basic screen calibrations first.

It is getting mostly great reviews (Amazon, for example) but read them first. Some photographers preferred more expensive calibrators but they are not as easy for me to carry around.

Just out from Tiger Color.

Ultra Color Picker. $20US

Hi there!

Great tools, this is the one i use: http://www.colorschemer.com/

ColorSchemer Studio it's a color web design focused tool, very simple to use. Among other things, has a color wheel, color harmonies and suggestions sets (from the color you pick), multiple color pick from images, screen picker, RGB and SL sliders for setting colors, HEX output code, etc.

One of my favourite features in ColorSchemer, is that allows you to save your color schemes and submit them to the ColorSchemer Gallery, where users can comment it and rate.

The desktop app comes for PC and Mac, and there's an online tool too.

Hope you like it. Greetings!

i have 83 links in my blinklist, all can to help, sometimes tools, sometimes, theory.... http://www.blinklist.com/sant...ura/color/