MAC Firewerk the Room is a warm red with a sparkle finish that is limited edition and retails for $21.00. In comparison, Natasha Denona Purpure (147M) is a warm red with a sparkle finish that is discontinued and retails for $29.00.
Natasha Denona Purpure (147M) is 90% similar — it is more shimmery, darker, cooler.
