The good news is that tortoiseshell hair works for all brunettes, whether you have warm or cool undertones. However, the trend looks best on anyone with wavy or curly hair versus straight hair, given the way the color is incorporated. As a result, Glamour UK recommends adding a few loose curls to make the color pop. While there is no one shade or color that works best for tortoiseshell hair, your colorist can customize the color based on your needs. It's therefore a good idea to bring a picture to the hair salon for reference.

But anyone considering tortoiseshell hair shouldn't go too light. "The highlights should be no more than 4 shades lighter than the base color to create a seamless and flattering blend," Matrix celebrity colorist George Papanikolas told Byrdie. One of the benefits to this look is that it doesn't require much maintenance. "If it's done well by a professional the grow out can be very soft and natural," Biolage brand ambassador Sunnie Brook shared with the outlet. "The clients I do this on see me once every three months." To help the color last, celebrity colorist Kari Hill recommends washing your hair every other day. Per HuffPost, L'Oréal Paris Color Vibrancy Dual Protect Spray and Instant Nourishing Treatment work well for tortoiseshell hair because they have UV filters and antioxidants to help retain moisture and shine. Looks like brunettes really can have more fun!