Is there something wrong with my extensions

[southcitybabe]

Just bought some euorpean hair extensions very pricey to what I normally get.

Anyway they came in bundles as usual but with them being folded in the packet they had a kink in the hair so I straightened it out only I noticed, after straightening the brown when I straightend the blonde it left a brown smudge on them

This has never happend before, is it normal? Its human hair so I cant see why this would happen..

Any idea whats going on or what I can do? I apply blonde and brown to my hair so when Im straightening I dont want it looking weird.