Onchor,
Other than just fishing them, I havent had them tested, and I do believe that almost all marabou turns darker in the water, and most will be almost black (including pink mark) light penatration does some strange things underwater, we know it takes light to make a color a color, unless it's glow in the dark, and can make its own image. as he states in his book, jigs are more effective in clear water, and this is true. although with the flourescent head colors, and flourescent beads, they can and do perform well in off colored water.
how many different color combinations does one need?? Mark, you'd **** yourself if you ever got a look into my jig boxes. if you think all you need is pink/black/white then you go for it.
you catch 90% of the Steelhead on what you fish with 90% of the time.
believe me, there are colors that will blow the old pink/white combo out of the water, in alot of conditions.
its all about color shifts, sunlight,or lack of it, the fish's position, background colors, ...the list goes on. I use the book as a refference, and always keep in mind what the fish is looking at.

Fuzzy

Silent Approach Jigs There IS a difference