Importance of 460nm red LEDs?

[khyberkitsune]

Almost every single commercial grower and most home growers get great flowers (HID) with virtually no 660nm, yet you see no puzzle?

http://www.hidhut.com/catalog/images/600HPS%20Lamp.jpg

I see TONS of 660 there for HPS. In fact there are almost NO lamps (besides monochromatic ones) that do NOT have 660 emissions of some sort.