According to Edelman, almost all hair needs to be prelightened for rainbow.
“I ask my clients to imagine they have a half white, half dark brown piece of paper in front of them,” said Edelman. “If they painted a pink line with watercolor paint across both halves, where would they see the color? Only on the white paper. Semipermanent hair color is the same: completely translucent.” She added, “You cannot get around the fact the hair needs to be lightened.”
In the world of hair dye, there is a color wheel that assigns numbers to (natural) hair colors, starting with one — black — and ending with platinum 10. To tint their strands with rainbow shades, brunettes need to lift their natural color to a minimum of a level six on the hair color wheel (which is the darkest shade of blond you can be without being a light brunette).
That said, if you are wary about making the plunge and fully committing to platinum blond, you can make the process easier on yourself and your hair. Try an ombré balayage style, which will fade nicely into a standard blond and require much less upkeep than a completely bleached foundation.
The rainbow hue you select will also indicate how much you should lighten your hair. “Blues and violets should have a level eight or nine base,” said Edelman. (These are pale blonds.) “For reds, oranges, and yellows, and greens, hair needs to be lifted to a level seven or eight,” but she acknowledged that red will be visible (albeit less powerful) on a level six blond. Those who feel passionate about achieving pastel hair should know that you must bleach your hair all the way to a “level 10 with minimal warmth” (white blond).
Now that you’re likely feeling more intrigued about pursuing colorful hair, we have good news. Edelman has divulged her favorite Fall/Winter rainbow styles that cater best to brunettes. Should you be convinced that you won’t be able to pull off your top pick with your complexion, don’t be: your skin tone should not be the ultimate deciding factor.
“Vivids are already breaking the rules,” she said. “You can rock anything as long as you’re sassy.” So whether you’re in search of a more subtle style or a vivid rainbow look, you’ll find some serious inspiration when you read on.