Ikea TRADFRI bulb E27 CWS opal 600lm gamut
These measurements were done with a colorimeter, not a spectrophotometer, so they're not a 100% correct but still a lot better than nothing.
Each measurement was done 10 times, then averaged, with the bulb at max brightness.
Though the bulbs can display a fairly deep red and a very blue blue, their reach on the green side is atrocious. It's barely green. If you plot it over a CIE xy plane you get this:
You have to hit just the right coordinates to get a deep blue or red but most things along the blue-green spectrum fall out of reach. Red-blue is a better story but still far from ideal.
It's essentially equivalent to Philips Hue Gamut B, but slightly better on the blue side of things. Probably not enough for anyone to notice though.