The main thing is to have a quality pair of glasses. Costa del mar,action optics hobie, and my favorite Maui Jims. 20 dollar cheapo sunglasses ,even polarized ones, do not protect your eyes. style is based on personal preference and lense color is determined by conditions. gray is a good "all around" lense.

Action Optics makes or at least made a pair of glasses with interchangable lenses.
2 years ago I bought a pair of Maui Jim's "typhoon" glasses with gray frames. They have been excellent for me but as with all quality eyewear they are spendy.

main thing is aviod cheap glasses they do not protect your eyes! also spend the extra 3 bucks for a croakie sunglasses rarely float