Why is Japan's largest snackmaker changing snacks' packaging to black & white?

Japan’s largest snackmaker, Calbee, is temporarily changing its brightly coloured packaging to black-and-white designs, as the Strait of Hormuz blockade has disrupted the supply of naphtha, a petroleum-derived raw material used in printing ink. Calbee said 14 of its products will shift to monochrome packaging by the end of May. Notably, Japan imports around 40% of naphtha from Middle East.