For type, the wilow makes more flash, so use it in clearer water. The coclorado produces more vibreation so use it in stained or muddy water. In ultra clear, try smaller blades, and go to one. The same with heavily pressured areas.
I fish mostly semi stained water so I go with either the double willow or a willow/colorado combo. Gold if cloudy and silver if clear skies.
I use a single colorado if Im thumping along the bottom or in colder water.
I use a single willow if Im ripping it through grass or off the bottom.
in stained water I like to use a Strike King redeye shad in chartruse because of the holographic blade. In muddy water a colorado is a definate and in clear water an average size willowleaf.
Gold blades on cloudy rainy days
Gold/Silver blades on overcast days
Silver blades for sunny days.
I use alot of double willow blades for burning baits for smallies. Also try mixing it up some on overcast days try using a chartruese willow in front and a silver blade and burn it as fast as you can. On a 1/2 oz bait I will scale my blades down to a #3.5 in front and a #4 in the back.