Artificial light and plant growth

Question: What color of artificial light works the best in plant growth?

Answer: Generally, a mixture of fluorescent and incandescent light
sources works very well. This produces a pretty good dose of all
of the important wavelengths. Either alone does not work as well.

Reference: http://www.newton.dep.anl.gov/askasc...9/bio99144.htm

I just happened to stumble across that while looking for something totally unrelated, but equally geeky!