My favorite Pike fly is the Reynold's Pike fly. It works so well I don't think color makes much if any difference. I tie them on a Mustad 37187 1/0 hook. I like Dahlberg Mega Divers too. I tie them with tails of big fly fiber and rabbit strip also. I tie all of my Pike flies pretty large. I try and make them as tough as possible because Pike are hard on flies. I use 5 minute epoxy instead of head cement. I use heart beads from the craft store to make the heads on the Reynold's Pike fly. The way they are tied plus the bead and epoxy, they are by far the toughest fly. Dahlberg's work pretty well, but not as well as Reynold's pike flies do and they get wrecked faster as well. I still like using them because it's fun to have a big fish smash a fly on the surface.
Here is a step by step on the Reynold's Pike fly;
Tie on a heavy, 30 - 40 lb. mono weed gaurd and epoxy it to the hook.
Tie on the tail, magnum rabbit strip. I use magnum strips because they are tougher.
Tie on a clump ( I use the whole feather ) of marabou, and flash. Don't overdo the flash. I think it works better with a smaller amount.
Palmer crosscut rabbit up the hook shank to about 1/4" from the eye. Make sure to cover all of the thread from the previous steps with the leather of the crosscut strip. pull the mono weed gaurd up through the eye and tie it to the shank all the way back to the rabbit. Pull the mono back over the top and tie it down and trim it.
Rough up a spot on the heart bead where the eyes go, mix up a battch of 5 minute epoxy and glue the eyes on and the bead on the head of the fly.
This is about as bullet proof a Pike fly as you can get. I make a bunch of different colors, but have had something happen to one, changed colors and seen no change in how they hit them. I really don't think color matters. On a side note, you may need to find a substitute hook. I have been looking for more of them and it's starting to look like they may have stopped making them in 1/0. You can still get them in 2, 4, and 6, but they are not big enough for this fly.
The Dahlberg Mega divers I generally tie on Mustad C52S BLN 2/0 hooks. I stack deer hair, but you don't need to. I like the way it looks but I don't think it helps you catch fish at all. You can do them as I said before with Rabbit tails.
Or big fly fiber.
There are other flies that work also, like flat wings, EP fiber flies and things like that. I tie a big surf candy like fly with Icelandic sheep that works pretty well. You can tie a bunch of different colors and try them. I tie a lot of different colors.
This is a more colorful Dahlberg with a tail made with Icelandic sheep.
I hope this gives you a start on it. If you have any questions let me know.