It depends on how dark the brown is. They are meant for light eyes and are for enhancing natural colours. On medium or dark brown eyes, they are invisible, or have a very minimal affect visible only under very bright lights. If your eyes are a light brown or hazel hue, the evergreens look nice (n light brown eyes they create a hazel effect and on hazel eyes they can make them appear more green). The royal blue and acqua seem to be invisible regardless of what type of brown your eyes are.

Good luck