And the red and blue is suposed to be used much better than the full spectrum lights.
red and blue is supposed to be theoretically more efficient, but I've found that plants grow a bit better under white than red and blue.
I suspect though a combination of white and red would be the most optimal combination.
In any case, the efficiency of cheaper red+blue lights often tend to be a bit lower than white LED, simply because there's been so much mass large scale production of white LED lamps, so that probably brings down the efficiency from what the spectral efficiency conversion to photosynthesis would otherwise be.
My general take is that if you have lower than optimal lighting levels and really want to reduce energy consumption, red+blue may be the way to go, but if you have higher lighting levels red+blue reach saturation sooner.
Anyway I don't think we're talking about any gigantic efficiency losses from going from a typical lower cost red+blue grow lamp to a white LED lamp, maybe 25 to 40 percent. Considering that grow areas often need a little bit of extra supplemental heating, this isn't really a loss at all.
In fact if you're using fluorescent lighting together with an electric heater and thinking about upgrading to more expensive LED to increase efficiency, I wouldn't even bother. You're not going to be saving energy. All forms of lighting are virtually 100 percent efficient, it's just they are dissipating a portion of their energy as heat, and if you need that heat they're not really any less efficient than an electric space heater at producing heat. Heating is likely going to take several times as much energy as lighting anyway.
Another reason why I suspect it may be more efficient (in terms of energy usage) to grow inside under artificial lights, if it helps hold the heat in, than inside a greenhouse that has to be constantly heated throughout the entire Winter.