When viewed with LED or fluorescent lights, such materials may appear to have a color different from those observed under sunlight, firelight, or incandescent light.
****
As any female shopper knows as clothing purchased in a department store looks entirely different when seen in sunlight.
Or a shopper for paint who trusts the chips in a story like Home Depot!
Some fluorescent lights are much better than others; I'm surprised I've not seen any vendor of a 'good' light offer point-of-sale materials which would include a tethered diffraction grating customers could use to look at the 'good' light or other lights nearby in the store, nor have I seen any testing lab publish charts showing the spectral characteristics of different bulbs. While it may be hard to define a good unified 'quality' number which would allow meaningful comparisons among crummy bulbs, I would think one could compare good bulbs by publishing the amplitude ratio between the strongest wavelength within a defined "visible light" range and the weakest. For some bulbs, that ratio would be in excess of 100dB, but I would expect some bulbs have improved to the point where the numbers would start being reasonable and comparable. I find it odd that people regard color temperature as a meaningful basis for comparison, when one could produce any desired color temperature using just two wavelengths of light (one wouldn't even need three!)
Actually, I just had another idea: I'm not sure how inexpensively one could print such a thing, but a bulb manufacturer could print a "freebie" flyer or card with a bunch of color swatches; half of each swatch would be printed with conventional broad-spectrum inks, and the other half would be printed with carefully-chosen narrow-spectrum inks which would match when viewed in daylight or in the light of the manufacturer's "good" bulb, but which would mismatch badly when viewed in the light of competitor's bulbs.