There is other similar applets that i encountered.

http://webphysics.davidson.edu/alumni/MiLee/java/bb_mjl.htm by Mike Lee & Wolfgang Christian.
http://webphysics.davidson.edu/Applets/BlackBody/BlackBody.html by Wolfgang Christian.
Like: the composite colors



http://phet.colorado.edu/simulations/sims.php?sim=Blackbody_Spectrum by University of Colorado - Michael Dubson, Kathy Perkins & Wendy Adams
[img]http://phet.colorado.edu/sims/blackbody-spectrum/blackbody-spectrum-screenshot.png[/img]
Like: fantastic, worksheets from contributors

http://www.compadre.org/osp/items/detail.cfm?ID=10528&S=2 [img]http://www.compadre.org/profiles/blackbody1.jpg[/img]
Blackbody Radiation: Frequency and Wavelength written by Jose Ignacio Fernández Palop
Like: the context of the black body diagram and the resultant color