Line 3 , ( L3 ) currently known as Zona UniversitÃ ria - Trinitat Nova , colored green and often simply referred to as LÃ nia verda ( `` Green line '' ) , is a metro line in Barcelona operated by TMB . â '' Line 3 , currently known as Zona UniversitÃ ria - Trinitat Nova , colored green and often simply referred to as LÃ nia verda ( `` Green line '' ) , is a metro line in Barcelona operated by TMB , and therefore part of the fare-integrated ATM transport network of the urban region .