Web colours (RGB) are very different to those available in print (CMYK).
Jemima Pereira's handy 4096 colour wheel enables you to find colours that will work for use on your website. Hover over the wheel to view colours, and click to choose a web-smart colour.
Read more at http://www.ficml.org/jemimap/style/color/wheel.html
Febooti's Online color chart provides HTML color codes (HEX, Smart and Web Safe) in a very accessible format. Simply click on the colour wheel to select a color and angle. A full color palette of the selected colour will be also displayed, along with its HEX (also, Smart and Web Safe) colour value.
Read more at http://www.febooti.com/products/iezoom/online-help/online-color-chart-picker.html
Updated December 2009