Everyone educated past freshman biology can answer: chlorophyll.
But science played a dirty trick— a bit of sophistry. Because whether by experimentation or experience it is proven that chlorophyll and greenness are inextricable, it is impossible by the same experience or experimentation to claim to first graders, post-grads, or great-grandpas that chlorophyll is “why grass is green.”
As if chlorophyll makes grass green. Anything making something else implies a will. I am not arguing for a minute that there is nothing that makes grass green, but I am stating for all eternity that it isn't chlorophyll.
When it comes to green grass, it is just as scientific and certainly more historically accurate—in the sense of one thing causing another—to say green grass made chlorophyll. Some scientists might say I am splitting chromosomes if I needle them and ask what makes chlorophyll. But my point is neither DNA nor chlorophyll is the problem or the answer to why grass is green. It is the modern scientist's claim of who or what makes what that is the problem. It is the fact that a person walks outside in the morning and the grass beneath his feet is green--not chlorophyll or martians or envy--that asks a question; a deep question about creation and will; unlike the shallow question modern science magically answers by layering one upon the next, a thin pastiche of complicated terms.
Why is grass short rather than tall as a giant beanstalk?
I am simply trying to point out, at the risk of growing my grass too long, it is more correct to say lawnmowers make grass short than grass DNA does. Because the location of will is properly positioned.
I might as well say that eyes make men see. No they don’t. Eyes and seeing are the same thing. Eyes didn’t come before seeing. They arrived at the exact same time. Man wasn’t made to see by his eyes, but he does see. Why?