Zelda uses a single color tile (of the same color--green) but of a dark shade to create the illusion of little grassy patches. If you're familiar with the game, you'll know it's used VERY sparingly. It relies much more on the variety of terrain, rocks, trees, fences, dirt roads, and so on, to create a more organic environment.
Because I'm currently working on something similar, and I have Earthbound on the brain, that's another good example. It uses simple colors and single small "grassy knolls" to break up the monotony.