Just culture really, I suppose. Latino people can be anywhere from very dark to very light in skin tone. Eyes can be any color and they can speak a variety of languages. Most of my friends would identify as Latino and two only speak English, one speaks English and broken Mexican Spanish, another speaks both fluent English and Guatamalan Spanish.
Honestly, it's a terribly generic word to describe a wide range of fairly unrelated people, much like the word "Asian." I would just refer to people by what country they are from. If they are from the USA, regardless if they're white, brown, black, they're all Americans. For Canada, Canadians, Mexico, Mexicans, etc.