Guero/Guera

Whitey. Pale one. Honkey.
Guero is for guys, guera for girls. When used among friends, it's like calling someone dude. When used with people you don't know...watch your ass.

Oddly in the Mexican culture, Guero is not generally derogatory as Gringo is. Whitey or White man seems more derogatory than foreigner, but its not. Guero is preferable in the MX culture, while still slang. I have been called this many times by MX friends and acquaintances, and are very clear its not a pejorative.