MAC I've Got a Crush on You is a neutral duochrome with a metallic finish that is limited edition and retails for $32.50. In comparison, Natasha Denona Calypso Blue (05M) is a warm duochrome with a sparkle finish that is permanent in palette and retails for $29.00.
Natasha Denona Calypso Blue (05M) is 80% similar — it is cooler.