For those like me who didn't know what CRI is, it stands for color rendering index, and appears to represent how well the colors of things appear when lit by a light source.
Unfortunately it’s relatively limited, there are only a small number of wavelengths which are measured, and you can game it by tuning the peaks of the bulb to match up with those points.
There are better measures, but almost no manufacturers use them. I think just having the output spectrum and eyeballing it will do the trick.
[0]: https://en.m.wikipedia.org/wiki/Color_rendering_index
[1]: https://en.m.wikipedia.org/wiki/High-CRI_LED_lighting