Could they break? I use it for my laptop, I guess that's because
That comes from the color of the jeans and the dirt particles in the air.
Was it somewhere where it was wet and there was something blue nearby?
Can't be because I've never put the headphones in my pocket, only use them at home
No
It's because of your lard fingers
No.
It is normal for white cables to tarnish in any color over time. In itself, however, this is not a sign that they will break, and your laptop should not be to blame either.
Are you concerned with the discoloration of the cable sheathing? The electrical signal doesn't care what color the jacket of the insulation is.
The discoloration could come from many environmental factors. Maybe the material reacts with your hand perspiration and therefore discolors.
But this happens to me for the first time and I used it for my laptop for the first time
What was your methodology to rule out reactions to skin fat?
That would also interest me.