The white paint wore off while the black one didn't

That’s probably UV degradation, Most white paint is made from Titanium Dioxide, while most blacks use more stable elements.

UV radiation can eat trough the binding element in paints and leave the titanium dioxide around as a dust.

Source: I remember going down some internet rabbi thole years ago, someone please correct me if I’m stupid.

Also the text is in all caps because it’s in the mountains

Yet another shining example to reinforce the hypothesis that black don’t crack.