I would think if they are made of the same material as the 750F1 badges, the metal is actually gold coloured, not plated. In the past we have put scratched/gouged badges across a linisher to get back to undamaged metal, with no colour change or loss. It could be that the badges you have are replicas, or ones from another Honda have been fitted, or for whatever reason Honda made a batch in different base metal and didn't make a note of it.