Is it permissible to use a cosmetic product to conceal dark areas on the face?

A woman is not permitted to apply cosmetics when leaving her home with her face uncovered, even if the purpose is to conceal facial imperfections, due to the Almighty's saying: "And not display their adornment except that which is apparent thereof." However, if the face is covered, or if the woman is not in the presence of non-mahram men, there is no harm in doing so.