Sheldon Allan Silverstein - Vegetables

Eat a tomato and you'll turn red
(I don't think that's really so);
Eat a carrot and you'll turn orange
(Still and all, you never know);
Eat some spinach and you'll turn green
(I'm not saying that it's true
But that's what I heard, and so
I thought I'd pass it on to you).

Sheldon Allan Silverstein

http://www.poemhunter.com/poem/vegetables-2/