Cenizas translates to 'ashes'. It's a powerfully poetic word used to create one of the song's most memorable and melancholic images.
In the iconic line, "No le enviaré cenizas de rosas" (I won't send her ashes of roses), the word symbolizes a love that has completely burned out. This rejection of a dramatic gesture perfectly captures the song's theme of a 'light' love that was fleeting and left nothing substantial behind.
Soda Stereo gives us an explosive rock anthem that keeps things remarkably simple. The narrator looks back on a past relationship, waking up with the memory of someone who fell asleep "al calor de las masas" ("in the heat of the crowds"). He admits that he thought about writing to her to confess that "nunca sorteé las trampas del amor" ("I never dodged the traps of love"). The Spanish verb sortear literally means to dodge, draw lots, or navigate around obstacles, showing that love tripped him up every single time without mercy.
Instead of drowning in dramatic heartbreak, the singer refuses to send "cenizas de rosas" ("ashes of roses") or run away from "un roce secreto" ("a secret touch"). He accepts the relationship for what it was: "de música ligera" ("of light music"), a breezy, effortless pop tune that came, played out, and ended cleanly. By the time the chorus hits, he repeats "nada más queda" ("nothing else remains") until it turns into a total release. Nothing protects you from it, but once it is gone, it leaves no messy baggage behind.