Id help please? beautiful coloured bowl signed to base something RIO

The first letter i cant really make out but am guessing is CLGIINO RIO what can you tell me about this maker?

Brazil?

before i was thinking Italy but you might be right because of the RIO

Rio means river in Spanish so I think this could be from Spain??

I thought it might say "Aguiro", which could be Martina (mother) or Diego (son) Aguiro, Pueblo Potters from New Mexico. Nice theory, and the signatures look quite alike (http://www.adobegallery.com/art/ohkay-owingeh-polychrome-pictorial-jar) but pictures of the Aguinos' redware pots with geometrical decoration don't look anything like your bowl, and I can't find any connection between them and anywhere called Rio.

It might be worthwhile to email a Pueblo Pottery gallery or collector to confirm or otherwise. There are a few listed on Google.