Still, blonde hair requires toner to keep it from getting yellow or brassy, and toner, like any hair color, fades after a while. “I typically have [my clients] come in every 6 to 8 weeks to refresh the tone.” And in between visits, Kaitlin sends them home with tinted conditioner. Saturated in blue or violet shades, these conditioners are made to counteract blonde hair that’s going too yellow.

Try this: Blondes Baby Blonde Conditioner by Rusk ($14.61)

How should you maintain hair dyed brown or red?

Minimize the effects of heat styling. When it comes to natural colors, “it’s the direct heat applied to hair that causes fading,” says Kaitlin. And because it’s not realistic to expect her clients to avoid the hair dryer or flat iron, she highly recommends applying a heat protectant before styling.

Try this: Botanical Blends Healthy Hair Growth and Heat Protection Oil ($16.99)  

What are the best ways to keep “unicorn” colors bright?

The single best thing you can do to maintain a vibrant unicorn color is to wash your hair as little as possible. When your hair starts looking dingy, pull it into a ponytail or spray it with some dry shampoo.

Try this: Batiste Dry Shampoo (starting at $6.49)

When you have no other choice but to shampoo, check out co-wash. Short for “conditioner wash,” co-washes were originally formulated for curly tops, but they’re also good for colored hair. Focus on the roots, where the oils accumulate—”the fewer bubbles, the less harsh it will be on your hair color.”

Another, less optimal tip, at least for me, is to wash your hair with water as cold as you can stand it.

Try this: Aunt Jackie's Flaxseed Purify Me, Co-Wash Cleanser ($6.98)

Finally, when you condition, consider a color-depositing conditioner. You might not be able to match the exact shade of your hair, but the color will at least stay more saturated for longer. Kaitlin recommends the conditioners over the shampoos, as the pH “can be harsh on colored hair.”

Try this: CHI Ionic Color Illuminate Conditioner ($13.99)