People with darker blonde, light brunette, or highlighted hair (brand-cited level 6-8) whose color turns orange or brassy between salon visits. Not the right shampoo for very light/icy blondes - Oligo directs those to its violet toning version instead.

Where a generic purple shampoo is built for platinum blondes, this one is calibrated specifically for the orange brassiness that shows up on darker blonde, light brunette, or highlighted hair, pairing the blue-toning step with argan oil so hair isn't left as stripped-feeling as it can be with harsher, sulfate-heavy toning shampoos.

Apply to wet hair and work into a lather, focusing on the lengths most prone to brassiness. Leave on briefly (starting short and increasing slightly if more correction is needed) before rinsing thoroughly - over-leaving any blue toning shampoo risks an ashy over-cast. Follow with conditioner as normal.

Pros:

• Purpose-built for darker/warmer blonde brass rather than a single toning shade for all blondes
• Free of sulfates, parabens, formaldehyde-releasers, MI/MCI, and gluten (brand claim)
• Includes argan oil for conditioning alongside the toning step

Cons:

• Brand does not publicly detail how its toning technology works beyond general blue-cancels-orange color theory
• Blue toning shampoos can over-tone or leave a faint blue-grey cast if over-used or used on hair lighter than intended
• Premium price point relative to mass-market blue/purple shampoos