I notice for all my dark denims that the color on the knee parts always rubbed off. After a few months of wear (only occasionally; not on a daily basis), the color on the knees fades and my jeans would look nice and dark all over except for these patches on the knee (which is looking lighter). I actually paid more attention to how i wear the jeans (I don't kneel, I try to straighten my knee when I sit.. etc) but it still fades. Does anyone else have this problem or is it just me/or my jeans? I saw other pictures posted on the site and everyone's jeans look great -- no patches!! Any suggestions Plz??