MAC Kelly Yum-Yum is a cool fuchsia with a satin finish that is limited edition and retails for $19.00. In comparison, Obsessive Compulsive Cosmetics Nylon is a cool fuchsia with a cream finish that is discontinued and retails for $18.00.
Obsessive Compulsive Cosmetics Nylon is 90% similar — it is brighter, cooler.