Interesting find when stripping down inside part of rims

[resq302]

Today, while I was stripping the paint off of the inside (back) part of the magnum 500 rim, I noticed that there was a layer of yellow, almost canary yellow, under the black paint.  Has anyone ever noticed this before?  This is the second rim I am stripping out of the five on my car and so far, this is the only one that I have seen yellow on.  Did that signify something or is it that someone probably painted it yellow for some reason over the years.  I have only stripped the back of the rim so far and have not gotten to the front as it started to get too cold.

Just curious if anyone has come across this or if this yellow paint meant anything?

[Chryco Psycho]

I have seen yellow on the Ralley rims but on the inner band covered by the tire