Multiracial Americans
A typical Latino American family may have members with a wide range of racial phenotypes, meaning a Hispanic couple may have children who look white and African and/or Native American and/or Asian. Latino Americans have several self-identifications; most Latinos identify as white in terms of race, while others identify as black and/or Native American and/or Asian. Latinos who do not want to identify as one of those identify simply as Hispanic and/or "some other race" as their race.
White Americans
The characterization of Middle Eastern and North African Americans as white has been a matter of controversy. In the early 20th century, peoples of Arab descent were sometimes denied entry into the United States because they were characterized as nonwhite. In 1944, the law changed, and Middle Eastern and North African peoples were granted white status. The U.S. Census is currently revisiting the issue, and considering creating a separate racial category for Middle Eastern and North African Americans in the 2020 Census. 
In cases where individuals do not self-identify, the U.S. census parameters for race give each national origin a racial value.