Gueros is a Spanish slang term for a fair skinned or light haired person. Although it is not derogatory, it coud be used that way.
Mexico's Aeromexico airline and its advertising agency are apologizing for a producer's casting call requesting that only light-skinned people apply for a planned TV commercial.
Because Mexicans are largely dark-skinned, it is news to us why Mexican television ads routinely feature light-skinned actors, sparking accusations of racial discrimination. Perhaps because the leading Spanish-language TV network has two very popular and successful gueros.
The word is pronounced "where-oh" and it is slang for a fair-skinned or fair-haired people. It can be considered as the Spanish-language equivalent of "whitey".