Brown mascara is a popular choice among many celebrities because of its subtle yet impactful effect. It's a versatile product that can enhance the natural beauty of the eyes without being too overpowering. Here are a few celebrities who swear by brown mascara:

1. Jennifer Aniston: Known for her natural, girl-next-door beauty, Jennifer Aniston often opts for brown mascara. It gives her lashes a softer look, which complements her blue eyes and sun-kissed complexion.

2. Meghan Markle: The Duchess of Sussex is a fan of brown mascara. She often uses it for her lower lashes to create a softer, more natural look.

3. Emma Watson: The British actress and activist prefers brown mascara for a more understated look. It enhances her lashes without making them look too dramatic.

4. Gwyneth Paltrow: The founder of Goop, a clean beauty brand, Gwyneth Paltrow is known for her minimalist makeup routine. She often chooses brown mascara to subtly define her lashes.

5. Kate Middleton: The Duchess of Cambridge often opts for brown mascara to enhance her hazel eyes. It gives her a more natural and elegant look.

6. Jessica Alba: The actress and founder of Honest Beauty, Jessica Alba often uses brown mascara to create a softer, more natural look.

Remember, the choice of mascara color should depend on your personal preference, your skin tone, and the color of your eyes. Brown mascara is a great option if you're going for a more natural, understated look. It's also a good choice for daytime wear.