can we talk about how light colour is given in K (Kelvin?), so blue light would be “warmer” and red light would be “colder”?

This also tracks with Star spectral classes where extremely hot stars are blue-white (OB), followed by white (AF) and then the colder, orangish (GKM), before moving into red brown dwarves.

Yet when we talk about light temperatures its the other way round.