The Expert Guide to Coloring Your Own Hair—and Getting It Right the First Time

Get your hair ready a week before coloring

The process of dying your hair doesn't start when you set up shop in the bathroom, says hairstylist Jules Annen. A week prior, you should multi-mask your hair in preparation for the transformation it's about to endure. She suggests applying a clarifying treatment, a protein treatment, and a conditioning treatment, to ensure your hair is as healthy as possible. This not only makes your color more even but will prolong the life of the new shade, too.

Try these: Redken Extreme Anti-Damage Protein Reconstructing Rinse-Off Treatment ($23; ulta.com), Moroccan Oil Restorative Hair Mask ($43; sephora.com), Biosilk Restorative Hair Treatment ($28; ulta.com).

Choose your color wisely

Much like makeup, hair color should complement your skin tone and complexion. Generally speaking, hair color is classified as warm, cool, or neutral, and it's vital to stay within your spectrum when you're dying your hair at home. Warm colors have golden undertones that create the effect of sunlight hitting your hair, while neutral shades will be similar to your natural hair color but more vibrant, says Christopher Cilione, a senior colorist at Oscar Blandi Salon. If you happen to fall on the cool end of the spectrum, Cilione doesn't recommend dying your hair at home, since it can be tricky to pull off. And if you get it wrong, you may be left with a grayish cast.

If you're not sure of your classification, take a peek at your wardrobe to see what colors flatter you most. If they're warm (yellow, tomato red), go for warm shades. But if they're cool (lavender, royal blue), choose a neutral color. If you're a mix? You can probably test out many colors, but seek a professional's advice for best results.

Prep your space

There's nothing worse than a big hair color stain in you bathroom, which can be very difficult to clean or remove. Before you mix anything or even touch your hair, prep your workspace. You'll want to have a protective cloth, like an old sheet, towel, newspaper, or plastic, that covers your tub and sink. Colorist Harry Josh suggests tucking your shower curtain up over the rod. He also says it's smart to turn your showerhead to the gentle setting, since a strong flow of water can send dye droplets flying when you rinse, causing stains.

Finally, look at the instructions of the color kit. Most will list essential supplies, like a bottle applicator, comb, and hair clips. Lay everything out for easy access. And if your set doesn't come with plastic gloves, make sure to buy some since you want your hair to be colored, not your fingers.

Test dyes on a small section of hair

The scariest part about dying your hair at home is worrying about the outcome. Instead of applying color and hoping for the best, celebrity hairstylist Andrew Fitzsimons suggests using a small patch of hair to see how the color responds. Since you shouldn't attempt a dramatic change at home—like going from dark brown hair to red—a patch test underneath your hair shouldn't be noticeable to anyone but you. Annens suggests applying a tiny amount of dye behind your ear and leaving it on for three hours before washing. Then, let the color sit for 48 hours to see how it shades into your hair. This is a great indicator of what will happen from root to end when you dye your entire head.

Don't forget that hair color also impacts your skin. Many people have adverse reactions to chemicals, which can cause a burning or irritating sensation. Annen suggests doing the same test to your skin, ensuring you won't feel as if your head is on fire when you dye your hair. She suggests applying a dot of dye to your inner elbow to see how your skin responds.

If testing out your color isn't an option, look for a hair color that closely resembles your natural color, or choose a product like Clairol Natural Instincts ($8; ulta.com), an ammonia-free formula that enhances color and shine, but will not lighten hair.

Start applying color an inch or two away from your scalp

The heat from your hair tends to make the color develop faster at your roots than it does at the ends of your hair, says Fitzsimons. He recommends starting an inch or two away from your scalp, so you don't end up with two different shades. When you're halfway done with your all-over color, apply the dye to your roots for best results.

Protect your hairline

Though most people remember to protect their bathroom tiles and hands from dye, Annen says many forget about their scalp. Or more to the point: their hairline. This small strip isn't a place you give much attention to, but if it suddenly turns a new shade, you won't be able to see anything else. When you're applying hair color, she suggests using clear lip balm, petroleum jelly, or another moisturizing gel to keep the formula from staining this area.

Try this: Aquaphor Lip Balm ($4; target.com)

Focus on roots to avoid damaging colored hair

If your color looks good but some natural regrowth or a few grays are starting to appear, you don't have to dye your whole head. In fact, when you dye too often, you run the risk of drying out your strands, which can leave your hair brittle and crunchy to the touch. Instead, you should focus on the roots. To do this, you can either buy the same kit you originally used or get a root touch-up kit to smooth the dye down just to where your old color starts. If you have highlights, use a rattail comb to section off only the pieces that need color. If you're worried about dripping on the rest of your hair while touching up the roots, Annen has a solution: conditioner. Apply a dab to the ends of your hair and then rinse your whole head once the dye has settled and the color won't bleed onto the areas you're trying to avoid. Consider it your goof-proof ticket to a precise root touch-up.

Another option is to skip the root touch-up and opt for a temporary transfer-proof root concealer. Fitzsimons suggests Rita Hazan Root Concealer Touch-Up Spray ($35; sephora.com), which comes in a wide variety of shades and colors that complement most tones and hues.