[AngelicaDeAlquezar]

None between "castaño" and "marrón" when talking about hair (in Mexico it's only "castaño").
I have only heard "ojos marrón" or "ojos cafés" (most common in Mexico).
"Moreno" is mostly used about skin. You don't say "tiene el cabello moreno", but you may well hear "es una persona morena". In that case, they would probably have to explain if they're talking about a person with dark hair or with dark skin.