When growing out gray, you may notice that the grays follow their own unique pattern, per Hairstory. You may have light grays, dark, grays, and even white strands all intermingled throughout your head. There is no clear-cut way to predict how or where they'll appear, which is beautiful but can also be frustrating if you're trying to cover specific areas. That's why herringbone highlights work perfectly.
Herringbone highlights are meant to resemble the blended parallel look often found in flooring which was created to mimic the pattern of fishbones. However, it doesn't cover your grays. Instead, it compliments them by weaving very fine and thin highlights around them. The result is a wonderfully blended mix of highlights, lowlights, and natural grays.
"I've always used the herringbone highlight technique, which involves applying foils at an angle in a herringbone pattern — because I like delicately blended color," colorist Zoe Irwin tells Vogue. "It's about seamlessly blending a mix of shades together, as opposed to completely hiding the gray."