I have used evaporust on schwinns, raleighs, a puch, gt, trek, and a Scott.
Everything from 15 to 35 years old and with decals ranging from under the clear coat to on top and in good shape to on top and flaking.

It hasn't affected any decals yet.
And I've used it on all sorts of paint colors- it doesn't affect paint.

The real benefit of that stuff is with rusty components.