Chlorophyll is green because it does not absorb most of the green part of the sun's visible spectrum, instead absorbing mostly light from the red and blue ends of the spectrum. As for the height of the sexes, it's most likely that a number of factors are involved, including natural selection (taller men more successful in combat in them good ol' caveman days, to put it ludicrously simply, and/or women tending to select taller men for their sexual partners), genetics, the different phases within growth spurts during and after puberty, and, quite likely, extra testosterone for blokes. Then we can talk about dietary considerations, and why the average height of all humans has increased over the centuries. Looking things up increases the chances of avoiding silly answers.