Ingredient Intelligence
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Basic Violet 2

A synthetic violet cationic dye depositing on hair to neutralise brassiness in purple shampoos. Deposits preferentially on damaged hair sections.

Benefits
  • Neutralises yellow/brassy tones via complementary colour principles
  • Deposits selectively on porous, damaged hair sections
  • Temporary toning — washes out over successive shampoos
  • Strong colour intensity at low concentrations
  • No bleaching required — colour deposit mechanism
Example uses
  • Purple shampoos
  • Toning conditioners
  • Colour-depositing masks
  • Blue-black toning haircare
  • Brass-neutralising treatments
Mechanism of action
Basic Violet 2 is a cationic triphenylmethane dye. The positive charge on the dye molecule adsorbs electrostatically to the negatively charged, bleached/damaged cortical surface. The violet colour (complementary to yellow/orange) absorbs wavelengths 580–620 nm (yellow-orange) and reflects wavelengths 400–450 nm (violet), visually neutralising warm/brassy tones via subtractive colour mixing.
Clinical evidence · High

Toning mechanism definitively characterised. Safety assessed by CIR and SCCS.

Effective concentration range
0.001–0.1% in purple shampoos
Formulation notes
Cationic dye — deposits on anionic hair surface via electrostatic interaction. Contact time critical — over-deposition causes visible purple/blue discolouration. Low pH increases deposition efficiency.
Watchouts
Cationic synthetic dye — excluded from strict natural/COSMOS formulations. Staining risk if misused (too long contact time or on very porous hair).
Market positioning
Sold as brass-neutralising toning active. The colour chemistry is sound and the mechanism is genuinely effective. Natural-beauty exclusion is appropriate for COSMOS-certified products.
Comedogenicity

0 / 5

Sensitisation risk

Low

INCI & aliases

Basic Violet 2

CI 42520 · rhodamine B hexyl ester · ethyl violet

Clean beauty perception

Excluded from strict natural beauty frameworks. Accepted in clean prestige haircare. Deposit-and-rinse purple shampoo mechanism well understood by consumers.

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