Thats pretty much what I would do. I print colors, then spend ~20 mins looking at all the colors at the LHS. They carry the Model Masters line as well, and it has tons of shades of blue & gray...
I just did a little more researching and found another board that said about using Floquil "Light Blue". http://www.railroad.net/forums/viewtopic.php?f=32&t=59157
The problem is, Pantone is an industry standard on colors. However, besides house paint, no one really makes paint that follows the pantone color system.
If you can get the actual color of the decals, and bring it to your local home depot, or a paint store like sherwin-williams, they can scan it and mix up a matching color.
Another good place to go is an automotive shop where they can scan the paint, and sell you a can of automotive paint designed for plastic bumpers.
house paints are not meant to be sprayed and will be very thick.
the automotive plastic bumper paint will work as it is meant to be sprayed
