Hilary Duff’s Cool Blue Formulas
By Nikki Lee
The perfect blue shade doesn’t exist—wait, it totally does thanks to Nine Zero One Salon co-owner and celeb stylist Nikki Lee (@nikkilee901)! Nikki gave our dream girl Hilary Duff a full-foil highlight and mixed up some cool shades for the perfect blue blend. Keep scrollin’ for the color formulas, how-to and a pro tip to prevent unwanted green tones!
Nikki’s Celeb Color Notes:
“Hilary is no stranger to a fun hair color,” said Nikki. “She colored her own hair teal during lockdown. This mix of blues just hits different on her though! She is goals in many ways, but to be pregnant and rock this color with so much confidence is everything!”
Who Did It
Products Used
COLOR FORMULAS 
FORMULA STEPS
1. Start with a full head highlight application using Formula A. Nikki tapped in Nine Zero One co-owner Riawna Capri (@riawna) to start in the back while Nikki started in the front and both worked toward the middle. “Thank god I had my bestie Riawna to help me because we put in what felt like hundreds of foils,” says Nikki.
2. After processing, pre-tone with Formula B to kick out any unwanted yellow before applying the blue formulas. Pre-toning is KEY to prevent the yellow and blue from mixing and creating green finished results.
3. Next, apply Formula C from the roots to midlengths.
4. Apply Formula D to the ends.
5. Process, rinse and apply In Common’s Crystal Cashmere deep conditioning treatment to lock and seal everything in.
6. Finished Look – The baby bump and cool blue combo is literally too cute to handle!
