With the right experience, you will find sevear colors in both types that will block the signal. Some real good examples are the pearls and metallic.

To really understand what I'm talking about here, I would suggest that you cover your plane in MonoKote pearl yellow, or any of the UltraCote metallics, place your antenna wire COMPLETELY inside the fuselage and hang on once it's in flight. I speak from experience, a lot of it, and after reading some of the suggestions of the manufacturers themselves.