A good reference is the Wasco fish taxidermy manual. Painting a fish and a bait that catches fish are very similar. I don't think you need every single color used in taxidermy, but it will give you a good idea where to start.
But the biggest cheat sheet of all is to look at a lot of other peoples work. 99% of what you see was copied from another painter. Some may copy color for color and some may add their own little variation. And ALWAYS cheat when you can, ie; use tape, stencils, combs, bottle caps, lufas, panty hose, hair nets, or whatever to make it easier.