I ran across this video about White LED vs Purple LED Side by Side using the same DWC bucket for both Lighting tests the Results are pretty significant . So if you had questions about LED grow lights like i have had this will really show you the difference in the two types of lights.
I grow with LEC’s white light it isn’t just the white it is the CRI (color rendering index) research is finding that plants are using more colors in between red and blue. Many of the new leds on market now are Cree cobs or SMD which all favor a higher CRI whiter light
I second what @Donaldj is saying. The higher cri options giving us a shift of intensity to wavelengths more productive for plants. To the point where color temp almost takes a backseat to cri. I wouldn’t at all be surprised if a 4000k high cri could out flower something like a 3000k 70-80 cri. In the past that would be a pretty unrealistic expectation.
The higher Color Rendering Index COBS have more complex phosphors. You need a more even spectrum to get good Color Rendering. Narrow blue plus narrow yellow may look white to us, but a better phosphor mix has all those in between wavelengths and makes a lot of different colors look like they would under bright sunlight. That’s a high CRI score. They may also hit some absorption wavelength in the plants.
The real problem with colored LEDs is they each have one wavelength in a very narrow band. That collection of narrow bands may miss something the plant needs. COBs have a blue LED that stimulates some phosphors to emit light in a broad range of different wavelengths. Apparently, the result is you don’t miss those critical absorption peaks.