Davines Alchemic Conditioner Silver, $29; davines.com Redken BBB Spray, $20; redken.com Christophe Robin Shade Variation Care in Baby Blond, $52; net-a-porter.com Sachajuan Silver Conditioner, $30; bloomingdales.com Shu Uemura Color Lustre Cool Blonde, $58; shuuemuraartofhair-usa.com