How come I'm smart enough to see Mexican are not white?

I think the census data are not right most of the Mexican are mixed or brown skin are label as white which I think it not fair most of the white in the Mexico are immigration from Europe and even some white American live their their some question of their citizenship in Mexico. American fail to see Mexico is also a immigration country also got problem with their illegals from Central American and South American. Mexico even got black living their former slaves from American that escape the slavery in American went to Mexico. Mexico never had slaver most of their black live their free most of the live on the southern coastal state, Mexico did had a black president that way before any of us where even born, he's name was Vicente Guerrero was president in 1829 . It like I say Mexico is a immigrant country they got Asian.black, Europe, even people from other Latin American country.