Non sum qualis eram bonae sub regno Cynarae
bought red mouth
She's a prostitute. The adjective order matters—'bought' comes first, 'red' (suggesting passion) second. He's paying for what looks like desire.
roses vs lilies
Roses are red, sensual, cheap. Lilies are white, pure, funeral flowers. He's trying to drown out death/purity with paid pleasure.
madder music
'Madder' means both 'more insane' and literally madder—a red dye. Everything he wants is louder, stronger, more intense. It's not working.
the lamps expire
Lamps don't just go out—they 'expire,' like living things. The party dies, and so does his distraction.