The plot above is for the same CFL spectrum found previously but with a gamma correction applied to the vertical scale. The relative heights of the peaks are probably dependent on the formula for converting the RGB values to a B&W value. The function that my computer uses to convert a color image to B&W shows a stronger response to the G values which one would expect since the eye is most sensitive to 555 nm. I probably need to look for a better conversion formula.
edit: The eye's response to light of different wavelengths is measured by the luminosity function. The RGB values are determined by the color matching functions. All four depend on the illuminant since the spectral power density is a function of wavelength. The conversion formula used may assume a standard illuminant.