Why do yellow filters always have a sort of random speckled pattern on them where white filters are just white?
Just tradition, I think. Originally cigarettes with filters were colored in pattern that resemble natural cork (it’s that “yellow random speckled pattern”). But nowadays it’s not always true, and some (mostly light) cigarettes now are all white. Or, like my favourite - all black.
Early cigarette filters were made of cork. The pattern you describe is intended to mimic its look.
Oh, god…I’m having flashbacks to my sophomore year in college…