Some other overviews-
Visible LEDs are traditionally rated in “lumens”, which is entirely about visibility. The scale is adjusted for human eye response (reading under the light, actually), not actual output energy, and this heavily favors green since human eyes are very sensitive to green. Far red is the opposite case, it takes much more total light energy per lumen. IR LEDs cannot be rated in “lumens” as they have no visible light.
Plants do not follow the lumen scale. There’s two well-established peaks of photosynthesis usage in the far-red and blue areas. There’s a lot of discussion on the utility of other wavelengths and it’s plant-specific. The term “photosynthetically active radiation” is used instead of lumens to compare light sources. You might think green is important for PAR, because leaves are green, but leaves appear green because it’s a wavelength it does NOT use and reflects it back.
All “regular” red LEDs are too far from the PAR peak for the red. There’s no reason they can’t be made, but just a terrible choice for control panels and stuff because deep red is not very visible for the amount of power needed. You need “deep red” LEDs specifically for “agriculture” or “grow”. 5 yrs ago they were really hard to acquire, now huge emitters are cheap.
There is a target flux density per unit area of a leaf. More is not all that helpful. A big part of this game is even illumination of the leaves. e.g. you may have a 2"x2" 100W LED emitter that casts light over ~180 deg, on paper, has plenty of power for a plant. We first note how much light is lost- the great majority, actually- off to the side if placed far from the plant. So we place it 3" above a plant so very little light spills out, but then we’ve got a spot of intense light on a few leaves in the middle, like 10x more than that leaf can use, and the other 95% of the plant is under-illuminated. Thus all that reflective mylar material to homogenize the light via chaotic reflections.
People have long observed that the rate a plant gains height in will change quite a bit with the wavelengths of light used. It’s species-specific.