This happened to me with my first artisan kitchenaid! It was loud and was leaking oil. I returned it after calling kitchenaid. The one I just got it happened at first but I cleaned with vinegar and it’s good now. If you wash your bowl and then dry it, it will not have any gray coming off. BUT if you take a small bit of shortening and rub it in the bowl with a paper towel, you will see it come off. Use vinegar to clean your bowl thoroughly then wash with hot soapy water and it should do the trick. I had to wash my new bowl 3 times with vinegar to get it all off, but it works. Hope this helps.