As was mentioned during the lecture, the energy carried by a photon is inversely proportionate to the wavelength. So the red light actually carries less energy than blue light! This is counterintuitive to me because generally red light is warm color whereas blue light is cold color.

@goku2021 yes, somewhat counterintuitive. However, blue flame occurs in the hotter parts of the fire rather than the rest parts of the fire, and the heat that is associated with some color that is radiated is proportional to its temperature for other colors as well (like green). Perhaps humans consider red to be a more agitated color relative to a more muted blue on a subjective level (when in reality, the energy make up of each is inversely related). This probably has to do with the natural occurrence of red in the environment.