Ever wanted to pick the brain of a beauty editor? Or get beauty product recommendations from someone who has tried them all? You’ve come to the right place. In our weekly series, beauty editor Hana Hong answers your biggest skincare, hair care, and makeup questions, all submitted by Real Simple readers. Tune in every Tuesday and submit your own burning beauty questions here for a chance to be featured.

Reader question: I got a permanent color done professionally two months ago, but my hair is already a different color from when I left the salon. Why is this happening? —Dara Moynes

In an ideal world, the hair color that you walk out with at the salon would be the hair color that stays at home. Alas in the real world, hair color fades, which means that it oxidizes and changes over time.

You’ve probably heard about oxidation in chemistry class, where clear formulas (or foods) can warp into a brownish hue when exposed to environmental aggressors. The same goes for your hair: At a microscopic level, hair color molecules can lose electrons, triggering a chemical reaction that turns hair brassy.

Depending on your hair color, the brassy shade will show up differently. Blonde hair will appear yellow or orange, whereas a brunette or someone with black-colored hair may start to notice their locks looking orange or red. This can happen for a lot of reasons—some of them inevitable and completely unavoidable—like hard water exposure and UV rays, i.e. just living life. But don’t worry—you can prevent your color from changing by implementing smart hair maintenance practices, which starts by not making these mistakes below.

Hair Color Mistakes

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Using the wrong shampoo and conditioner

You can pay top dollar and have a pro colorist working on your hair, but your efforts can (literally) go down the drain every time you use the wrong product in the shower. That’s because a lot of hair care products contain sulfates, which are great at keeping hair feeling smooth, not-so-great at maintaining hair color. “Sulfates contain sulfuric acid, which can penetrate the hair color and remove color pigment,” says Stephanie Brown, colorist at IGK Salon in New York City. “To prevent fading, ensure you are using a color-safe shampoo and conditioner that is sulfate-free, like IGK Pay Day Instant Repair Shampoo ($31; ulta.com) and Conditioner ($31; ulta.com).” Another color-safe option is Purelogy Strength Cure, one of our favorite shampoos for damaged hair.

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Washing with hot water

As wonderful as hot showers feel, the cooler the better when it comes to color maintenance. That’s because heat raises the cuticle, giving color an easy escape route. However, we know cold showers are easier said than done—to make the drop in temperature more tolerable, start out in lukewarm water, and then slowly adjust the meter until it’s cool.

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Overusing hot tools

Remember what we talked about above: heat = bad. Our hair would be more durable if we avoided heat-styling all together, but that’s not a reality for most people. Unfortunately, hot tools can make brassiness come out faster, so make sure to add a heat protectant before styling. Richy Kandasamy, colorist and R+Co Collective Member, recommends looking for something that includes heat and UV protection for when you leave the house—just like your skin requires SPF to keep it safe against UV damage, so do your strands. Try a hair detangler like Rahua Hydration Detangler + UV Barrier.

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Frequent swimming

Sorry, beach bums—chlorine and salt water both work against your favor. “They can strip the hair of its luster, making the hair appear dull,” says Brown. “Extended time in water also keeps the hair cuticle open longer than usual, allowing the color molecules to be stripped from the hair. Consider putting your hair in a swim cap or avoid wetting your hair in the water. If you must, apply a generous amount of hair oil to help protect the cuticle from water molecules.”

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Not applying toner

From masks and shampoos to glosses and conditioning treatments, toning products can eliminate unwanted brassy and red tones and revive your strands. They work like a semi-permanent dye by depositing certain pigments that cancel out tones you don’t want to see. The best part? You can do it yourself with at-home toners so you don’t find yourself in the stylist’s chair every other week.

One important note: Jana Rago, a salon owner, hairstylist, and colorist, says toner is like a temporary bandage, since it’s not a permanent solution. To maintain your preferred shade, you’ll need a toner every month to six weeks, dependent on your hair texture and how often you wash your hair.

And if all else fails, book a color-corrective appointment with a professional stylist/colorist to give your brassy hue a complete makeover. They’ll most likely use a stronger toner to hide warm undertones and help blend the colors together.