Hair Colouring Theory and Application Flashcards

What is the law of colour that explains how to neutralize unwanted tones?

Answer: Complementary colours (opposites on the colour wheel) neutralize each other

Complementary colours, which sit directly opposite each other on the colour wheel, neutralize each other when combined. For example, green neutralizes red, violet neutralizes yellow, and blue neutralizes orange.

What colour would you use to neutralize unwanted brassy orange tones in lightened hair?

Answer: Blue

Blue is the complementary colour to orange on the colour wheel. Adding blue-based toner or colour to brassy orange hair will neutralize the unwanted warmth and create a cooler, ashier result.

What is the difference between semi-permanent and demi-permanent hair colour?

Answer: Semi-permanent coats the cuticle and fades in 4-6 shampoos; demi-permanent penetrates slightly and lasts 12-26 shampoos

Semi-permanent colour deposits colour on the cuticle without developer and fades in about 4-6 shampoos. Demi-permanent uses a low-volume developer to partially penetrate the cuticle, lasting 12-26 shampoos with gradual fading.

What is a toner and when is it used?

Answer: A semi- or demi-permanent product applied after lightening to achieve the desired final shade and neutralize unwanted tones

A toner is typically a semi- or demi-permanent colour applied after pre-lightening (bleaching) to achieve the desired finished shade. It neutralizes unwanted warm undertones and adds the target hue.

What is a strand test used for in hair colouring?

Answer: To evaluate how the hair will respond to the colour formula by testing a small section first

A strand test involves applying the colour formula to a small section of hair to evaluate processing time, colour result, and the hair's reaction before committing to a full application. It helps prevent unwanted outcomes.

What does 'deposit only' mean in hair colouring?

Answer: The colour adds pigment to the hair without lifting or lightening the natural colour

Deposit-only colour adds pigment to the hair without using a developer strong enough to lift or lighten the natural melanin. Semi-permanent colours are always deposit-only, and demi-permanent colours are primarily deposit with minimal lift.