Can give my insight
Well, you gotta remember that in most lower depths, most colors go to shades of black, depending on depth. Some colors do work better in higher depths or clearer conditions.
Ok, one of my favorite plugs that outperforms is a green metalic tadpolly custom dipped with a black bill. Second is a plain metalic pink tadpolly. This is steelhead mind you. When it comes to salmon. I run bigger K15-16 baitwrapped kwikfish. Usually in chrome only. I assume those manage to similite fish. But I only use warts on the tidal flux areas of rivers. I like chrome only! Hot pink in the magnum sized in tribs. But chrome in standard wiggle wart size with either an orange or black stripe down back. I cast them like spoons and retrieve. Fish hit them VEROCIOUSLY!!!! I can only describe as watching a steelhead rise to a dry. I've literally watched silvers and kings follow my warts to the boat and attack. Talk about a rush. So, I designed some of my flies to somewhat resemble the best I could to a wart for silvers. These I assume resemble baitfish, since they attack as if they're going to eat (I watched one of my 20+# silvers completely ENGULF a standard wiggle wart!!!!). Say it this way, he came into the boat no problems. LOL.
So, depends on where you're at. I think in the rivers, unless you're near redds, they are attacking because they're miffed. In the tidal flux, they're after baitfish. I've never run plugs for summerruns, so not sure if my theory would hold out. I know most of my patterns I PURPOSELY tie like crawdads and sculpins. I tie up a retrofitted GP for fishing the Nooch. All in shades of brown and oranges. Very effictively flies.