Unlike most people on The Simpsons, the East Asian characters aren’t yellow.
In defiance of traditional cartoon conventions, while most of the principal characters in The Simpsons are yellow, the East Asian characters (such as Akira, the Japanese restaurateur, or the ladies in the picture) have a whiter skin tone. The writers have actually lampooned the weird skin color decisions for the cartoon on the show. When Homer was afraid his children were going to turn into mutants he said “They’ll be horrible freaks with pink skin, no overbites, and 5 fingers on each hand!”. Then the camera cuts to the “mutant” versions of Bart, Lisa, and Maggie, who look completely normal.
To clarify, the reason we say “East Asian” instead of “Asian” is to distinguish between people from countries such as Thailand and China and characters such as Apu, who is from India and sports a darker brown skin tone.