If you have taken a look at Ajax.Asp.Net 'Atlas' QuickStart Developer Tasks > Controls and UI "A Simple Example", you may have noticed that you can't immediately run this example on your own machine. The site makes the source code for the example available, but it does not provide a link for the stylesheet "intro.css". Without the stylesheet, the color selector functionality fails.
I am providing intro.css for download here. Just save it in the same location as the web page on your local machine, and "A Simple Example" will work correctly.
FWIW, I obtained the stylesheet using Fiddler.