Hiked down to the bottom of Snoqualmie Falls. I am always arrested by such Green. If you're interested, here's a pithy wikipedia article on the theory of color vision. In essence, the human eye is twice as sensitive to green as to the other primaries. Most digital camera sensors, by the way, have twice as many green pixels as red or blue ones.
One theory, in evolutionary terms, of why this is, is quite simple. Green means food.
Eat your veggies.