Giffard Parfait Amour is a dark bluish purple liqueur and part of their classic liqueur line. They say it comes from a very old recipe with notes of violet, geranium, orange, and vanilla.
Giffard is a French company specializing in a wide variety of liqueurs and eua-de-vie among other products. Some of those extra products are flavored cocktail syrups (or "sirop"). They are generally sweetened with pure cane sugar.