I have seen a teardown of a LIFX bulb and it uses a RGBW emitter approach. The Philips Hue uses a completely different combination of emitters: amber, phosphor-converted lime, and blue.
The RGBW approach used in the LIFX bulb gives it an average CRI of 88-89, peaking at over 92 between 3100-3400K, according to a comment from a representative of the company which was
posted on Amazon.
The specs for the Philips Hue bulb says it has a CRI above 80 between 2000-4000K, and it has a CRI of 91 at 2700K. This might not sound as good in terms of CRI, but the choice of emitters does allow the light to have better color rendering when the bulb is strongly color-tinted (which is the whole reason people buy a color tunable bulb in the first place). That LIFX bulb is going to make the surroundings in your room look pretty monochromatic if it is set to a yellowish-green lime color, or is set to a heavy pink rose tint. Most people do not stop to think about what the color rendering is going to be like in off-white color mode.