Cor-de-rosa literally translates to "color of rose" or "pink". It's a charming and slightly more poetic way to say "pink" in Portuguese, often carrying connotations of sweetness, innocence, or even a romanticized view.
In the song, it appears in the phrase "Mentiras cor-de-rosa" (rose-colored lies). This evokes the idea of harmless, beautiful lies, or perhaps lies that paint a more optimistic picture, making them more palatable and less damaging than harsh truths. It's an evocative phrase that captures the song's theme of desiring comforting illusions.