Black and white patterns on rockets were originally intended as roll patterns. They helped as a visual back-up for acceleration sensors measuring the roll, as discussed in this previous question What is the purpose of the black-and-white patterns on some rockets?.
However, many modern rockets don't have these patterns, implying they are no longer necessary, which makes sense as accelerometers have become more than accurate enough to just smack on a few extra for redundancy and be fine, I'd assume.
Nonetheless a few recent missiles revealed by North Korea do have these roll patterns (see for example this ICBM or sub-marine launched missiles). I find this quite weird as I'd assume North Korea to have access to modern accelerometers through China.
So the real question becomes: Could there be other reasons to have these black and white patterns apart from aiding in roll measurements?
Or do the North Koreans just like the old school look of the rockets as much as I do?