Reading· Madrid
'Azul, Amarillo, Danubio
I don't have enough information to confidently summarize this event. "Azul, Amarillo, Danubio" translates from Spanish as "Blue, Yellow, Danube," which could refer to many things — perhaps a sporting regatta on the Danube River (whose blue and yellow are notable colors), a cultural festival, or something else entirely.
Source: Ayuntamiento de Madrid — datos.madrid.es · CC BY 4.0