Wow! no need to tag 2 threads to ask same question. This one going back to May of 06. Yes, what Cellar2ful said.
I don't believe it is a sun fade alone as the color fade is even on both lid and bowl on older black MBH. I think it is more of heat from cooking and some sun fade over time that changes black pigment in the porcelain to change to grey. Not so much on newer blacks.
Best bet is to use the search button. Tons of threads on faded black comes up. If nothing comes up, or want more clear answers , I think it is better to create a new thread dedicated to the topic. This way, next guy with a same question can do a search and find the answer. Just a thought. Not just for OP but all of us including myself as I have done it before too.