Fom the Harvard-Smithsonian Center for Astrophysics, this site show
the spectrums of fluorescent light, sunlight, and a LED red light (light
emitting diode) using demonstration
software.
http://mo-www.harvard.edu/Java/MiniSpectroscopy.html
This Web page allows you to explore additive and subtractive
color mixing in a hands-on activity. You can also combine color pigments
(cyan, magenta, yellow) in different proportions to make any possible
color. You will need to have a Java enabled browser (Netscape 3.0 or
Internet Explorer 3.0 or higher). http://wigner.byu.edu/Colors/TabbedcolorBox.html
The Web site from the Harvard-Smithsonian Center for Astrophysics
dedicated to education, resources, and news about the Chandra mission
http://chandra.harvard.edu/