Avalon ,discoloration of ceramic tweeter

I have the Avalon Opus, but the tweeters have a light brown discoloration in the center.
The spots are about half a inch.
The dutch importer of Avalon told me that it has been caused due to ver loud playing , for a short time.
And that it`s no problem , no warranty issue.

Will the tweeters cause problems in the future?
I also own the Avalon Opus, and I do not play them loud. My pair have a light ring of discoloration around the center of the tweeter, so I called Avalon. I was told that the discoloration is generally normal and not a problem.

Basically it comes from a small amount of ferrofluid coming in contact with the ceramic through the gap of the voice coil. If you can hear a problem in the tweeter, or you cant hear the tweeter then you can have them replaced, but tech support at Avalon said they have received tweeters back that were almost completely black in the center that still played and measured correctly.

Thanks for the responces.

I have never played them loud.
Bought the Avalons used , with 6 months warranty (ended in May).
The dutch importer did listen to the tweeter, and it was sounding fine .
His explanation is similar to Aljordan`s.
If you look at one of my systempictures you see a new 30 mm new thiel tweeter with s slight coloration this one came straight new out of the box and plays fine