Sleek MakeUP Sunset #6 is a cool blue with a frost finish that is permanent in palette and retails for $9.99. In comparison, Natasha Denona Petroleum Blue (92M) is a cool blue with a pearl finish that is permanent in palette and retails for $29.00.
Natasha Denona Petroleum Blue (92M) is 85% similar — it is darker, more muted.