shades of green. All of them! (OK, MOST of them.)
I like that being GREEN means being environmentally aware. I'm forever finding bottles to recycle, if not return. There is even a GREEN Party in New York State, and other parts of the world.
GREEN means GO, a great affirmation.
Of course, GREEN has some negative connotations as well.
It conveys the idea of something, or someone, not mature, deficient in training or sophistication or experience.
Worse, it suggests one of the seven deadly sins, as in green with envy, the green-eyed monster.
Still, lots of great songs that start with GREEN (all linked; chart numbers from Billboard (US) Top 100).
Green, Green - New Christy Minstrels (#14 in 1963)
Green, Green Grass of Home - Tom Jones (#11 in 1967)
Green Onions - Booker T and the MGs (#3 in 1962)
Green River - Creedence Clearwater Revival (#2 in 1969)
Green Tambourine - the Lemon Pipers (#1 in 1968)