U.S. selective colleges are notoriously secretive about how they evaluate applications, especially with regard to how diversity informs admissions decisions. Even prior to the Supreme Court’s recent decision to ban race-based affirmative action, the contours of diversity have been contested and murky, especially for applicants whose identities are variably classified and interpreted, such as mixed-race applicants. Through qualitative case studies, collected during one of the final admissions cycles where race-based affirmative action was legal, I show how multiracial-identifying applicants and their families discern the boundaries of diversity. Do they contribute to diversity, and to what extent? Are they viewed as distinct or similar to other racial minorities? And what do their identities mean?: Do they represent a novel form of diversity, or a diluted one? The conclusions these families draw to questions like these I deem identity appraisals. Identity appraisals help explain applicant behavior, including how they identify, which schools they apply to, and for which opportunities they deem themselves eligible. Through these family portraits, I show the variable meanings ascribed to racial identities and diversity in selective US selective college admissions, and comment on how these meanings might have contributed to affirmative action’s recent downfall. I also consider alternative pathways to achieving diversity in the current political landscape.