As I understand it, Amber & Brown are colors for all-around conditions. Orange & Coipper are for light-colored western streams & shallow saltwater. Gray & Blue are for deep salt.
Here’s something that was forwarded to me this morning, the lens simulator might answer some questions. If nothing else, it’s a fun and informative use of the web. At least I thought so.
The Smith site is really something. Problem is, my AO brown lens tint things sorta brown with a yellow cast, certainly not the blue represented on the site. Great for freshwater, but not for me on the flats. Grey works much better for me. I’m beginning to think that the “best” lens color is like the “best” 5 weight.