Sydney Grace Forget-Her-Not is a cool purple with a pearl finish that is permanent in palette and retails for $6.25. In comparison, Natasha Denona Blue Dahlia (181DC) is a cool purple with a metallic finish that is limited edition and retails for $29.00.
Natasha Denona Blue Dahlia (181DC) is 85% similar — it is more shimmery, lighter, more muted.