Hello,
This is not really true. You do not need full spectrum at all. This is the misconception that allows vendors to charge outrageous prices for their so called "full spectrum" bulbs. Plants have the ability to change the color of the incident light into other colors to fit their needs. Discussed and argued in the thread containing the post=>
Fundamentals of Aquatic Lighting
We allow ourselves to be fleeced by the vendors because of our tacit agreement that spectrum is more important than it actually is. Hobbyists never really study this subject because it's a very difficult subject. As a result, we simply accept the opinions of the majority of others. The problem is, no one has actually ever proven that any "full spectrum" bulb grows plants any better than an ordinary bulb found in a supermarket or office building. Folks just assume that the majority opinion is correct without any data to show for it. In effect, might=right.
Was anyone aware, for example, that ADA bulbs were never "full-spectrum"? In fact, the bulbs are extremely high in green. So much so that the fluorescent bulbs actually have the model name "NA Green". No one argues the growth rate and health of their gallery tanks, yet, no one has ever questioned why their bulbs are not "full spectrum". Their tanks are low light because, as you mentioned, the green, although delivering lower PAR than blue, penetrates deeper into the tissue allowing it to reach the chlorophyll cells located further beneath the surface, thereby improving the quantum yield.
Cheers,