MUST-HAVE KIT Garnier Nutrisse Nourishing Multi-Lights H3 Warm Bronze kit for medium to dark hair ($7; drugstore.com).
PRO TIP ?The longer the formula is on, the lighter hair becomes. Brown hair only needs about three minutes, or it gets too brassy,? says colorist Kyle White of N.Y.C.?s Oscar Blandi Salon.Read MoreLess