How to Find Your Best Wedding-Day Hair Color

A great hue starts with a single question: Are you warm or cool? It's your skin tone that determines what shades will look most natural. Think about warm gold and cool silver jewelry--people tend to stick with one or the other because it looks better on them. Your eyes, hair, and skin offer other clues.

1. EXAMINE YOUR IRISES

If they're flecked with yellow, chances are warm shades will complement your complexion best. Blue or green specks indicate a cool complexion.

2. FLIP YOUR WRISTS

Blood vessels will show green if you're warm, and blue if you're cool, says Giselle, a colorist at Riccardo Maggiore Salon in New York City. If you have a mix of the two, you're neutral.

3. HOLD BLUE FABRIC TO YOUR FACE

If skin appears more even and bright, you're on the cool side. If not, see whether an orange swatch does the trick, indicating you have a warm undertone. Should both look great, you're Switzerland.

4. INSPECT YOUR ROOTS

When soft 2 P.M. sunlight hits the un-dyed baby hairs around your hairline, they'll glint either warm gold or an array of reds; or cool gray or ash.

THE RESULTS

MOSTLY COOL ANSWERS

Opt for beige, champagne, wheat, and chocolate shades for your hair, says colorist Denis De Souza, of Andy LeCompte Salon in Los Angeles.

MOSTLY WARM

Ask for sunny honey, auburn, or chestnut accents.

NEUTRAL

Lucky you, both tones work!

Once you know your tone, it's time to book an appointment. Arrive freshly trimmed so the colorist can check out your hair's shape -- it will help her place color in the most realistic way. Be sure to mention the plan for your wedding style. "Painted face-framing wisps brighten features and define an updo's curves," says Lena Ott, a colorist in New York City. Wearing hair down? Prioritize your part and layers.

To keep your color looking great, avoid sunlight, over-washing, and hot tools, which can suck dye right out of your strands, says De Souza. Skip daily suds and absorb excess oils with a product like Drybar Detox Dry Shampoo (sephora.com).

Every few days, cleanse with a gentle, low-sulfate shampoo and conditioner, such as Rene Furterer Okara Radiance Enhancing Shampoo and Conditioner (shuuemuraartofhair-usa.com). Before styling, sweep a heat-protecting salve through damp hair. Shu Uemura Art of Hair Essence Absolue is full of camellia oil (shuuemuraartofhair-usa.com).

Healthy hair holds color the longest, so use a hydrating treatment just once a month; any more might cause build-up, cautions Giselle. Nigelle ER Treatment is extra moisturizing (milbon-usa.com).