Urban Decay Bend the Knee is a warm lavender with a metallic finish that is limited edition and retails for $19.00. In comparison, Natasha Denona Duet (431DC) is a warm lavender with a metallic finish that is limited edition and retails for $29.00.
Natasha Denona Duet (431DC) is 90% similar — it is more shimmery, darker, warmer.