Most are only 2 shifts, but some do change more based on the Kelvin temp. Really there is no such thing is CFL as the C stands for compate, but it is really fluorescent light reactive. This happens as fluorescent light is missing some of the color spectra so when the glass reflects the white light, some of that light is not there so it looks as if it changes.
We have seen some fluorescent shift glass change as 4000k, 5000k and 6000k and then another in normal sunlight. So it looks as 4 is the most out there so far.