YSL Nude Avant-Garde (91) is a warm pink with a luminous finish that is limited edition and retails for $38.00. In comparison, Guerlain Petal Blush (229) is a warm pink with a luminous finish that is permanent and retails for $39.00.
Guerlain Petal Blush (229) is 85% similar — it is less shimmery, darker, warmer.