This is the time when anything goes, says Jan Marie Arteca, a Ted Gibson colorist. Blondes, brunettes, and redheads can experiment with their hair as much as they'd like. You don't have to worry about covering gray yet, and you're young enough to play around with color.
Try color-depositing and enhancing shampoos and conditioners.
For black hair: CHI Organics Tone & Shine in Black Orchid
For red hair: Ted Gibson Color Shampoo and Conditioner in Copper
For blonde hair: Paul Mitchell Platinum Blonde Shampoo and Conditioner
For brown hair: L'Oréal Professional ARTEC Brunettes Color Depositing Shampoo