From the article, spectrum and colour temperature are related but not 1:1 matches to each other. A “2700K” light can apparently have quite a lot of blue in it s

From the article, spectrum and colour temperature are related but not 1:1 matches to each other. A “2700K” light can apparently have quite a lot of blue in it still. > If you go to a hardware store, you’ll almost certainly see a demo of light color temperatures in the bulb aisle (typically around 2700K for “warm” light, around 5000K for “cool” light). You can get to those average light warmths a wide range of ways, though, and so two different bulbs with the same color temperature may have very different spectrum plots to get to the same visible end result. Without running them through a spectrometer, you can’t tell the difference - our eyes simply don’t work like that.