For anyone with gray, white, silver, platinum-blonde, or lightened/bleached hair who wants to counteract yellow or brassy undertones between colour services.

Because it is a pigmented toning shampoo rather than a plain moisturizing shampoo, it's best suited to people who already have light-enough hair for violet pigment to show a toning effect — it will not lighten or tone hair that hasn't already been lightened, or hair that is darker than gray/white/blonde.

The reason to reach for a pigmented shampoo like this rather than a standard one is timing: brassiness on gray, white, or lightened hair builds up gradually between salon visits, and a violet-toning shampoo lets you manage it in the shower on your own schedule instead of waiting for the next appointment. Because the toning step and the cleansing step happen in one product, it also skips the extra 10–20 minutes a separate purple mask usually asks for.

• Apply to wet hair and massage into the scalp and through the lengths.
• Leave on for 1–2 minutes to let the violet pigment neutralize warm tones.
• Rinse thoroughly. Wearing gloves is recommended to avoid a temporary violet tint on hands.
• Follow with a conditioner or hair mask for hydration.

Pros

• Violet pigment is built into the shampoo itself, so toning happens during a normal wash instead of requiring a separate purple mask or gloss.
• Uses a coco-based sulfate (sodium coceth sulfate) rather than SLS/SLES, and is paraben- and sodium-chloride-free.
• Processing time is short (Biotop specifies 1–2 minutes), so it fits into a regular shower routine rather than needing a dedicated toning session.

Cons

• Contains multiple declared fragrance-allergen ingredients (hydroxycitronellal, alpha-isomethyl ionone, amyl salicylate), so it isn't a fragrance-allergen-free option despite some retailer listings describing it that way.
• The violet pigment can stain light towels, shower surfaces, and hands — gloves are recommended during application.
• Leaving it on longer than the recommended 1–2 minutes to chase a stronger tone risks over-toning hair with a visible purple/gray cast rather than just neutralizing brass.