If it really is that the chrome plating wore off, I wonder if these are still safe to use and also won't affect the beer flavor? I can't be the only one experiencing this. I'm surprised only a few have chimed in here.
I remember seeing several posts on the NB forum (which unfortunately are no longer accessible) about beer eventually eating through chrome plating in shanks and faucets. I really cannot tell what's going on with that shank from the picture though.
I'm using stainless steel elbow shanks from Micromatic and have not had any issues with discoloration.