2012
Easy color contrast ratios | Lea Verou
Browser support is IE10 and modern versions of Firefox, Safari, Chrome, Opera. Basic support for IE9. No responsive version yet, sorry (but you can always send pull requests!)
Color Oracle
by 1 otherColor Oracle is a free color blindness simulator for Window, Mac and Linux. It takes the guesswork out of designing for color blindness by showing you in real time what people with common color vision impairments will see.
Color Laboratory -- AWARE Center -- HTML Writers Guild
by 2 othersThis color laboratory allows you to select colors and see how they appear next to one another, and in various foreground/background combinations. It also allows you to see those colors as they might appear to color-blind users.
Color equivalents table
The 147 color keywords defined in SVG, as referenced by the CSS Color Module Level 3, along with their various numeric equivalents.
2011
La gestion des couleurs dans les navigateurs Internet
On le voit, le Web qui véhicule tant d'images est très mal servi par les navigateurs.
A Guide To Improve Your Website's Readability Through Colors
Colors have a huge effect on readability. This is why you need to choose them wisely so that they not only create esthetically pleasing combinations but also make it easier for users to read the text. Text is an integral part of any site and we shouldn’t punish visitors for coming to our site by using hard to read color combinations.