Regarding photosynthesis....see

http://photoscience.la.asu.edu/photosyn/education/photointro.html

I was only using it as an example of red light  absorbtion by green pigmentation. Rathe than an indepth treatise on photosynthesis.

The fact remains that for me in my system the green [and to a lesser extend black and purple]pens do have an effect.