If you look at the spectrum curve you can see that halogen lamps output alot of reds and yellows, while alot less greens and blues.
Some have said that halogen has poor color rendering, yet how does it get a high CRI of 100? What I keep coming back to is halogen does not produce enough colors and renders the scene too orange-yellow, yet some how it gets the high CRI.
CRI in relation to CCT. It’s comparison to a hypothetical source at the specified temperature.
So in your case, the halogen at approx. 2700K, has the same colour rendering as an ideal light source at 2700K.
Wikipedia link
^ what he said.
Incan doesn’t lack colors, the whole spectrum is there, but since they have a color temp of around 2700 K there is a lot more red than there is deep blue.
You can look at CRI as the smoothness or straitness of the curve. And the Kelvin rating the TILT of the curve.
Incadescent has a straight line, but very tilted towards reds.
4000k 98CRI has a straight line, that is not tilted.
6500k 98CRI has a straight line, that is tilted towards blue.
4000k 70cri has a jagged line, but is not tilted.
That is why the 2700k high cri hasn’t got all the colors equally, and the 6500k the same, even though the specter is good.