Oops, that sentence sounded lots better in my head actually

Sorry about the confusion. I'll try again. What I wanted to say, and I'm certainly no authority on any of this, was that he could try to use an even darker green for the shades on that left side, our left that is, to make it contrast more with the green he's using for the light tones on that same side. That way he'd get the same kind of contrast between the colours used on the left side as he now has on the right. Hope that's clears it up a bit.