Quote Originally Posted by Leigh B View Post
Color temperature is ONLY the ratio of red to blue light. It knows nothing about green.
This is not an accurate statement. Color temperature is based on the color content of a continuous spectrum (with a relatively smooth curve) emitted from a theoretical 'black body' at a given temperature in Kelvin. This spectrum does contain green light, and the emitted spectrum contains different ratios of short (blue) vs. long (red) wavelengths and all the wavelengths between them as the temperature rises or falls.

One of the problems with fluorescents is that their color spectrum has large spikes of certain colors depending on the phosphors used to coat the tube, often giving them a disproportionately greater green content (a 'spike' in the power spectrum) relative to black body radiation.

See the Wikipedia entry on color temperature, and especially the section on spectral power distribution near the end of the entry.

Modern flourescents are assigned color temperatures that are generally accurate in character, but the phosphor 'spikes' can cause them to be off somewhat from what you'd expect from black body spectral content.