MB-Tex Stained?

[TROVERMAN]

On my 95 E320 Wagon with light-colored (oyster?) MB-Tex interior, the driver's seat and armrest (on the driver's door) have been discolored, especially the piping on the seat. It is like a purple-ish color, and it isn't the end of the world, but the other seats are all perfect and look brand new. (the car has low miles) It wasn't like this when we bought it, and it must be from wearing something. My question is, is it common for light mb-tex to become stained, what to avoid wearing, and how do I clean it?

Thanks, TROVERMAN