Lheure Bleue Perfume by Guerlain, The name 'l'heure bleue' means 'the blue hour,' and guerlain's l'heure bleue definitely evokes that hour before dawn and after dusk, where the sky is lit that iridescent, jewel-like blue. The scent is a very classic, feminine floral, and blends together notes of rose, iris and jasmine to create a bouquet for the skin. Best for casual wearing, the fragrance is recommended especially for springtime, and daytime wear.