Dorado means "golden" and is used to describe something made of or colored like gold.
In the song, ROSALÍA sings, "Mi futuro será dorado" (My future will be golden). She's not talking about literal gold, but a future that is bright, precious, and valuable. She uses this beautiful word to contrast the priceless future she'll have with her love against the expensive material things she's ready to abandon, like her Rolls-Royce and fine china.
ROSALÍA takes luxury and literally sets it on fire here. She sings about striking a match against high-end status symbols, opening with the wild line "Mi luz la prenderé con el Rolls-Royce que quemaré" [I'll light my fire with the Rolls-Royce that I'll burn]. From there, out go the luxury designer heels ("Mis Jimmy Choos yo las tiraré" [My Jimmy Choos I'll throw away]), the fine china, the pearls, the caviar, and even her upright piano ("regalaré mi piano de pared" [I'll give away my upright piano]). It is dramatic, funny, and totally direct: she is stripping away every flashy possession to earn total peace of mind once there is "nada que perder" [nothing left to lose].
Her new currency is simply love ("Tu amor será mi capital" [Your love will be my capital]). Sitting together with a chilled glass of crisp white wine, she declares that the past has finally sunk right to the bottom of the glass: "En el fondo se hundió en mi Sauvignon Blanc" [At the bottom it sank in my Sauvignon Blanc]. It turns an everyday glass of wine into the ultimate reset button, leaving her confident that her future next to her favorite person is going to be completely golden.