Zafiros are "sapphires," the precious blue gemstones. This beautiful word is also the title of the song!
DannyLux uses it poetically to describe a lover's eyes as "ojos zafiros" (sapphire eyes). However, he immediately adds that they "brillan y mienten" (shine and they lie), creating a heartbreaking contrast. This one word perfectly captures the song's theme: a love that is beautiful on the surface but painfully deceptive underneath.
This song is all about the shock and confusion after a sudden breakup. DannyLux sings about building a life with someone, a relationship he compares to "Un fuego / Que va prendiendo lento" (A fire / that lights slowly), only for his partner to just put it out. One moment they're together, and then "En un instante fue que todo se perdió" (In an instant, everything was lost). He's left so bewildered that he imagines the morning sun asking him what happened, and he notices small, painful details like her clothes no longer being in the drawer.
The title, "Zafiro," which means sapphire, comes from the most cutting line in the song: "Esos ojos zafiros brillan y mienten / Creo que ni sienten" (Those sapphire eyes shine and lie / I think they don't even feel). He's describing someone beautiful but cold and maybe even deceptive. He's stuck between loving her and being hurt, admitting, "Pensar me haría odiar" (Thinking would make me hate). He feels totally alone, pretending to be okay while feeling like no one really knows him or cares enough to ask how he is.