Urban Decay Mirror is a cool taupe with a pearl finish that is limited edition and retails for $19.00. In comparison, Natasha Denona Deep Slate Gray (32P) is a neutral taupe with a pearl finish that is permanent in palette and retails for $29.00.
Natasha Denona Deep Slate Gray (32P) is 85% similar — it is more shimmery, darker, warmer.