I've heard that you can target the type of trout with lure color. Apparently silver spinner blades land more rainbows, gold for Browns, and bronze for brookies. Is this true? I've never tried to target species, I just fish for trout in general, but if this is generally accurate it could help target specific fish in the water I'm fishing.

I don't know about that. Fishing spinners for smallies, I have found color matters very little as long as its shiny. You will have to work harder with a colored blade to get bites, even on overcast days. I could pick up any silver or gold spinner and get bit. Size is more important than color. As for the trout I think if you have the right size spinner, be it silver or gold, you will probably catch browns in the deep pools and rainbows in the main current.  

I don't know about that. Fishing spinners for smallies, I have found color matters very little as long as its shiny. You will have to work harder with a colored blade to get bites, even on overcast days. I could pick up any silver or gold spinner and get bit. Size is more important than color. As for the trout I think if you have the right size spinner, be it silver or gold, you will probably catch browns in the deep pools and rainbows in the main current.

X2. I've found that color doesn't really matter, whether I'm fishing for smallmouth, rainbow trout, or brook trout. The size is more important. Location is also key, like mass bass said.

Color is not very important but I personal like the gold with red

I've always liked brown with a gold blade.

Color makes a huge difference for the trout here at times. I've seen days where two guys can fish side buy side with the exact same spoon and have one be silver and one be gold and one is outfishing the other by a big margin. I don't fish spinners for trout often but when I do I have the best luck on silver, gold, copper, or green (not chartreuse). 

Get rid of those spinners and get some soft plastics 

Not in my experience.

Trout colored spinners always work best for me.