MAC Humoresque is a warm duochrome with a sparkle finish that is limited edition and retails for $18.00. 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 95% similar — it is more shimmery, warmer.