White bicycles are never a good idea, especially a MTB.

Of the ideas in your OP, I really dislike the flat green and brown idea. That could easily go really wrong. Unless you're willing to paint every part, I generally encourage people to work around the colors of their components they have or are going to install. Most bike parts other than suspension forks are black, a few are white and very few are silver. It sounds boring, but I generally pick colors that work with black, white, silver.

I'm going to powdercoat my frame gloss black this winter. It's gunmetal grey right now, and all of my components are black or black/white, except my fork. Which is white with gold stanchions and blue knobs.. go Fox!