CRI & TLCI Rating
C.R.I, or color rendering index, is another attribute of the light that a fluorescent bulb emits and it is as important as the color temperature in determining the quality of the light. This is a calculated measurement of how accurately a given lamp “renders” colors. A theoretically prefect score is 100. a lamp with a high CRI (anything above 90) makes colors look rich and deep, whereas a lamp with a much lower CRI makes the same colors in a set or costume seem washed-out and sickly.
The index rating is a measure of the average appearance of eight standardized colors of intermediate saturation spread throughout the range of hues. It measures what wavelengths are missing from a lamp when compared to a theoretically perfect light source.
CRI is an especially important rating for fluorescent tubes because they are often missing significant portions of the spectrum. Fluorescent tubes are a discontinuous light source that could be missing a chunk of red and have a huge spike in the green range. Fluorescent bulbs are tricky things, and some can have emission at only a few select wavelengths, almost as bad as the pure red, green, blue light. It takes work to smooth out the spectrum into a smooth distribution of all colors, so you'll pay more for a high CRI bulb.
Because the Kelvin scale is based on the balanced radiation of a theoretical black body, it’s technically incorrect to classify fluorescent's on the Kelvin scale. Kelvin ratings for tubes with a low CRI are less meaningful, unlike for tubes with high CRI which emit a more even spectrum.