Interesting hypothesis. If he's 25% black, how much is via his Peruvian mother vs his American father?
Remember what happens when we assume.
Well, you could ask the question about yourself, but the answer wouldn't matter.
Homer Plessy, the Louisiana man who was arrested for sitting in a "white" car, in the case known as Plessy v. Ferguson which resulted in the Supreme Court's 1896 "separate but equal" doctrine, was one-eighth black, the same as Zimmerman. Plessy claimed that he shouldn't be considered black in terms of the Louisiana segregation law.