Couple of snippets for the Board that suggest that lure color doesn't matter, nor do rattling plugs outfish silent ones in general while buyers of Rapala lures should be changing the hooks and rings for most applications.
Check out
http://www.fieldandstream.com (click on 'fishing' and then 'archives') for Ken Schulz's article 'Fish Talk; They Listen'. It's a report of what Berkley's finding out on their lure tests on bass and rainbow trout (the two species they keep in their tanks). I thought there were three particularly interesting points in the article:
1. None of their tests have shown that bass or trout have a preference in colors.
2. Scent works only over a few inches, not feet. Plant-based scents don't work at all, while salt helps only a little.
3. Oil-based products (like WD-40) cannot be attractants because they don't disperse -- they just stay there.
On another topic, I met a Rapala employee and field tester (now that's a job!) while fishing yesterday in Singapore. Besides showing me some prototype plugs -- which looked awesome and caught a couple of fish as well -- he said that Rapala's tests have shown that plugs with sound DO NOT catch more fish under most conditions. In fact, silent plugs usually outfish plugs with sound under most applications. So why put rattlers in plugs? Because fisherman want the noise, and it's an easier way to add weight to a plug to enable it to be cast farther. (Fisherman want longer casting lures, too.)
I complained that the copper rings and hooks on the freshwater plugs were useless for my purposes and I had to change them before using them in Asia. He said that their market research showed that most anglers change the rings and hooks on Rapala's but as there was no consensus in the US and Europe as to what anglers wanted the best way was to keep the price of the lure down by continuing to use cheap rings and hooks, and let the buyer pick what he wanted. The exceptions were that anglers in Japan and Australia demand chemically sharpened 2x strong trebles on their lures and are willing to pay extra for these features out of the box.