Notice rusted gas cap bolt heads...

[Moncha]

How's about black chrome?

[Ldub]

Just so you know ahead of time...When disassembling the gas cap, make sure to get a finger behind the nut when removing the cap screws that hold the rubber stop bracket & the catch or you'll be buying new nuts too.
The cap screws are readily available in metric stainless at any "real" hardware store that has Dorman or similar fastener selection.
Ldub