I just took a look at the 20 ga youth model USH that I purchased for my son about a month ago. The gun has never been shot or exposed to the elements.
The hammer appears to be turning a brownish color. I don't really think it's rust but looks very similar to the discoloration that commonly occurs in Rem. 870's on the ring that slips over the magazine tube.
I don't see this happening on my 12 gauge that was purchased at the same time.
Is this normal?