Hair Colouring Theory and Application Flashcards

What is the purpose of a pre-lightening service?

Answer: To remove natural or artificial pigment from the hair to prepare it for the desired lighter shade

Pre-lightening (bleaching) removes natural melanin or artificial pigment from the hair to achieve a lighter base before applying the desired final colour. It is essential when the target shade is lighter than what permanent colour alone can achieve.

What is an ombre colour technique?

Answer: A gradual transition from darker roots to lighter ends

Ombre is a colour technique that features a gradual transition from darker colour at the roots to progressively lighter colour toward the ends. It creates a natural, lived-in, gradient effect.

What is the role of ammonia or its substitutes in permanent hair colour?

Answer: To swell the cuticle and raise the pH so colour molecules can enter the cortex

Ammonia (or ammonia substitutes like MEA) raises the pH of the colour mixture, causing the cuticle to swell and open. This allows the colour molecules and developer to penetrate into the cortex where the colour change occurs.

What is a retouch (root touch-up) application?

Answer: Applying colour only to the new growth at the roots to match the existing coloured lengths

A retouch applies colour only to the new growth (regrowth) at the roots to match the previously coloured mid-lengths and ends. This avoids over-processing the already coloured hair and prevents colour buildup.

What is colour buildup and how does it occur?

Answer: An accumulation of colour on previously treated ends from repeated overlapping applications, causing darker, dull results

Colour buildup occurs when permanent or demi-permanent colour is repeatedly applied over previously coloured hair (especially the ends). The accumulation of pigment makes the hair progressively darker, duller, and more difficult to lighten.

What are tertiary colours on the colour wheel?

Answer: Colours created by mixing a primary colour with an adjacent secondary colour

Tertiary colours are created by mixing a primary colour with an adjacent secondary colour. Examples include red-orange, yellow-green, and blue-violet. They provide more nuanced colour options for formulating.