Yeah, yeah I know It's just my poor sintaxis. When I started I never understood why would anyone care about colour temperature, if the real thing that matters to plants is light spectrum, so why labelling in kelvins and not in nanometres? . That's what surprised me most. And everyone seems to base their decisions on kelvins and not on spectrum. What I meant by blue light, was that when we studied the effects of light on pigments, Calvin cycle, Rusbisco,etc, the blue peak was ignored and we focused on the red peak of the light spectrum. At least with angiosperms. I will research more on the matter, but I suspect blue light is not as useful as red light for plants, and maybe that's why it was not mentioned.