By now, we’re well-versed on the difference between balayage and highlights, and caught up on the latest techniques, including oil slick color and palm painting. Still, there’s a lot of ground to cover on the basics of color. Naturally, the effort to figure out the facts of our color falls to the wayside when we sit back, relax, and peruse a glossy as our colorist puts in work. For anyone who’s ever had their hair colored, ask yourself: Did my colorist apply a semi permanent hair color? Or semi permanent’s cousin, demi permanent? Ahead, colorist Chris Greene from Meche Salon in Los Angeles, and editorial colorist Mauricio Bermudez, who mane-paints models like Katie Moore and Stella Maxwell out of SuiteCaroline Salon in NYC, break down the difference: semi permanent versus demi permanent.