What about Marcos Moreno? Or Carlos Zapatero?
I take your point that the origins of surnames in Spain are typically unlike those in e.g. England, but there are plenty of common apellidos originating in physical descriptions, (far away) place of origin, or livelihood.
This depends on the language. In Spanish (and by extension every romance language) no one would know the meaning of Alvarado (they would associate it with the name Álvaro, but just that) or González, but it would be awful to have a name like "Marcos Café/Marrón" (Marcus Brown) or "Carlos Panadero" (Carlos Baker).