WHO'S TO DYE FOR

Summer blonds have more stun – unless dark is better

Gentlemen prefer blondes — unless the would-be blondie looks better as a brunette. Women are dye-ing to lighten up this time of year, such as “Wolf of Wall Street” hottie Margot Robbie, who stepped out in London on Friday with reddish-gold locks that were a welcome sight after the dowdy brown ’do she’d been sporting since winter.

But some babes are better off embracing their dark side. Consider Hilary Duff, who’s been making her hair blonder and shorter this year, even though she looks much sexier with the rich chestnut mane she’s worn in the past.

“You always want what you don’t have, especially with hair color,” says Rick Wellman, co-owner of the Patrick Melville Salon. “But there are definitely people who are meant to be blond, and there are people e who are meant to be dark.”

So how do you find your true hue? Go back to your roots.

“Look at the hair color you had as a child,” says Wellman, whose clients include Mariska Hargitay and Brooke Shields. “That’s usually a good indication of what direction you should go in.”

Play it safe by staying within a range of two shades lighter to two shades darker than your current hair color.

“You want to enhance what you have,” says Ashley Ferrett, colorist at Serge Normant at the John Frieda Salon on Madison Ave.

Or experiment by test-driving two shades with the two-toned ombre look

seen on Emma Watson, Kylie Jenner and Jared Leto.

Your skin tone — not its color, but rather its undertone of warm (yellow to olive) or cool (pink to blue) — may be the most important factor in selecting the right shade.

“A pale skin tone can usually handle any blond color,” says celebrity stylist Louis Licari. “But if you have olive skin with yellow undertones, you have to avoid excessive golds, like yellow blond or light red, because it makes your skin look sallow.”

Beware selecting a very dark color if you’re very pale, because “it creates shadows around your face and makes you look tired and old, and no one wants that,” says Licari. (We’re looking at you, Reese Witherspoon.)

Here are tips before you mess with your tresses:

A new color could mean more trips to the salon.

“I’ll have to see a blond who goes brunette maybe twice a year,” says Ferrett. But a brunette who wants to go Lady Gaga blond will have to come in every two weeks as her dark roots return. Your hair’s texture also helps determine your perfect tint. Curly hair shines when it’s dyed a rich chocolate brown, but uber-blond can dry it out.

“If you make curly hair blond, it can look unconditioned or, even worse, fried,” says Licari. “Darker hair reflects the light better.” Don’t make the mistake of dyeing your brows the exact same shade as your new ’do, especially if you’re going blond.

“You want to see eyebrows, because it breaks up the space between your hair, forehead and face, and you want to have structure,” says celebrity colorist Rita Hazan, whose clients include Gwyneth Paltrow, Ashley Olsen and Beyoncé (who, frankly, can wear her hair any way she wants).

“Keep eyebrows natural, even if they’re a little darker than your hair,” she adds, but if they’re so dark that they’re distracting, you can lighten them a little. Don’t even think about color-treating your hair if it’s brittle or dehydrated.

“If your hair isn’t healthy, it won’t come out the right blond or the right brunette,” warns Hazan. “And you really want your color to look pretty in its natural state ... without having to blow-dry it, curl it and do too much for it.”