MAC Discotheque is a cool silver with a sparkle finish that is permanent and retails for $20.00. In comparison, Dior Trompe L'Oeil (011) is a cool silver with a frost finish that is limited edition and retails for $31.00.
Dior Trompe L'Oeil (011) is 90% similar — it is less shimmery, more muted.
