Fagulhando comes from the verb fagulhar, meaning to sparkle or flicker. It's a less common, more evocative word than simply saying something is shining.
In the song, the lyrics describe the couple as a Klimt painting, "'O Beijo' para sempre fagulhando em cores" (The Kiss forever sparkling in colors). This word beautifully captures the vibrant, enduring, and passionate nature of their love, like a constant, colorful spark.
Vanessa da Mata kicks off this upbeat pop track with a bold defense of taking romantic risks. She warns that the real failure is giving up before you even try: "Mas o pior não é não conseguir / É desistir de tentar" ("But the worst thing isn't failing / It's giving up on trying"). She points out how society conditions us to be cynical, noting that she grew up surrounded by bitter jokes and clichés about commitment, where settling down with someone (amasiar) or getting married was mocked, and opening your heart (se entregar) was viewed as a sign of weakness.
Instead of letting fear win, she imagines a future that defies time and decay. She compares her bond to Gustav Klimt's famous painting, declaring "nós somos um quadro de Klimt / 'O Beijo' para sempre fagulhando em cores" ("we are a Klimt painting / 'The Kiss' forever sparking in colors"). It is a vivid image that leads into an unashamedly sweet daydream: turning into two happy old people walking hand in hand on a sunny afternoon ("Dois velhos felizes / De mãos dadas numa tarde de sol").