I've got leather/suede seats and like most with these seats the drives side seat was badly scuffed.  So I applied some couch leather dye and they've come up rather nicely.  Better than I expected.  The "after" picture was taken a week after application and so far I've not suffered from any marks on my clothes.  It seems to have sealed well.
 
You can google "leather dye" but the stuff I used was: http://couchguard.com.au/leather/dye/colours.php
 
I also bought the application kit.  It contained cleaning alcohol.   All delivered for $35.
 
Hope this is of help.
 
Cheers
Colin