My first sentence was not as well formed as it could have been although if you had read a bit more closely you would have seen my point. Try this:

I'm no director of research - far from it... but my limited understanding tells me that plants do not use the entire light spectrum equally. In fact, they use quite limited amounts of white, yellow, orange and green.

The point being that plants do not need the same levels of white, yellow, orange or green as they do red and blue. They use almost no green spectrum (our plants are green because they reflect this light back rather than absorb it). A grow that benefits from direct sun light tells us nothing about their ability to absorption white, yellow, orange or green spectrum. That's just misplaced causality.

Thanks headshake, I knew that about white light and it occurred that I should up pack that but you did it for me.