Gold-tinted dog dishes

Hey guys:

I have a set of Plymouth dog dishes that I suspected of having a coat of paint on them. They did. After I stripped the paint off today, I noticed that they have gold anodizing on them, front and rear. There are spots of wear and the metal underneath is brighter.

So, what would these be found on and why the gold anodizing? And yes, it's anodizing, NOT paint.

Here's a pic with one of my regular caps for comparison.