Celaje has a beautiful double meaning. Literally, it refers to the patterns of light and color in the sky, especially during sunrise or sunset.
In this song, Rauw uses it poetically to mean a faint image or silhouette. He sings, "Tu celaje en otra yo vi" (I saw your silhouette in another girl), meaning he sees a ghostly trace of his ex in someone new—a powerful way to describe being haunted by a past love.
Rauw Alejandro is trying to move on from a breakup, but it's not going well. He thought he was over his ex, but he's just trying to distract himself with a wild lifestyle. He's in the club with other women, flying them on private jets from "De Sao Paulo a Nueva York" [From São Paulo to New York], and running up huge bills. But he admits, "¿A quién quiero engañar? Esto es pa' olvidarte" [Who am I trying to fool? This is to forget you].
No matter what he does, he can't escape her memory. He sees her face "en el humo" [in the smoke] and wishes for a time machine "Pa' borrarme tus besos de mí" [To erase your kisses from me]. He's with other women, but they just don't compare. He sees his ex's image in someone else, but she "no luce igual" [doesn't look the same]. This new life is so different from who he was that he says, "Ahora me veo y no me reconozco" [Now I look at myself and I don't recognize myself], which gives the song its title.