Wet 'n' Wild Royal Calyx is a cool lavender with a metallic finish that is permanent and retails for $4.99. In comparison, Melt Cosmetics Ultraviolet #1 is a cool purple with a frost finish that is limited edition and retails for $22.00.
Melt Cosmetics Ultraviolet #1 is 85% similar — it is less shimmery, darker.