artificial colour

Oxidative or non-oxidative colour products that are added to the hair in order to change its hue, level, or intensity.

average porosity

Hair absorbs moisture and chemical products at a common rate. Cuticle scales are intact and slightly raised.

colour wheel

A tool used by stylists for hair colour assessment and formulating

complementary colours

Colours which sit across from eachother on the colour wheel, and when mixed, cancel eachother out to create a grey/brown neutral colour.

cool colours

Colours that reflect blue, violet, or green.


The second layer of a hair strand, which provides hair with its strength and elasticity.


The area of the head located between the apex and the occipital bone.


The outer layer of a hair strand made up of overlapping scales.


The removal of pigment from the hair.


The amount of hair on the head.


An acidic product that is mixed with oxidative colour in order to oxidize and produce colour molecules.


The hair's ability to stretch and return to its original shape without snapping.


To add to the intensity or vibrance of a colour.

existing colour

The hue, level, and intensity that exists in a client's hair prior to a colour service. This could refer to natural colour or previous artificial colour.

extreme porosity

Hair readily absorbs moisture and chemical products. Cuticle scales are lifted and/or damaged.

head lice

A condition in which the head hair and the scalp is infected by the head louse. (Pediculosis Capitis)


A colour or shade.


The strength or saturation of colour.


The darkness or lightness of colour in relationship to other colours.

line of demarcation

The line where the natural regrowth meets the previously coloured hair.


The inner core of a hair strand, which gives hair its structure. Often missing from very fine hair.


Pigment that resides in the hair's cortex which gives hair its hue.


Colour that does not predominantly reflect a warm or cool tone.


To counteract or drab the intensity or hue of a colour.

non-oxidative colour

Colouring products that do not require the use or mixing of a developing agent such as hydrogen peroxide.


The process in which a developing agent combines with an oxidative colouring product to turn colourless molecules into coloured molecules for the purpose of hair colouring.

oxidative colour

Colouring products that require a developing agent, such as hydrogen peroxide, to oxidize and introduce colour molecules into the hair strand.

patch test

The intended colour product is applied to the inside of the elbow and behind the ear to determine if there are any sensitivities or allergies.

pH scale

A scale from 0 to 14 that is used to determine the acidity or alkalinity of various substances.


The hair's ability to absorb moisture or chemicals.

primary colours

"Pure" colours that cannot be created by mixing. They are red, blue, and yellow.


The degree to which the hair is lifted off the curve of the head.


A chronic skin disease that results in scaly, often itchy areas in patches on the body and scalp.

resistant porosity

Hair that does not readily absorb moisture or chemical products. Cuticle scales are tightly packed and smooth.


Ringworm of the scalp (tinea capitis) is a fungal infection of the scalp and hair shafts.


The amount of colour or lightener that is applied to a section of hair.


A condition caused by a tiny bug called the human itch mite. If these mites burrow into your scalp, your scalp can become quite itchy.

secondary colours

Colours created by mixing two primary colours. These are orange, green, and violet.

strand test

The intended colour formula is applied to a strand of hair to help determine end result.

tertiary colours

Colours created by mixing a primary colour with its neighboring secondary colour. They are yellow-orange, red-orange, red-violet, blue-violet, blue-green, and yellow-green.


The diameter of the hair strand. Texture can be described as fine, medium, or coarse.


The shade or hue.


The application of colour over pre-lightened hair.

underlying pigment

Any pigments that are exposed as hair is lightened through the 10 levels of lift.

uneven porosity

Hair that displays one or more types of porosity at different areas among the hair.

virgin hair

Hair that has not been altered with a chemical product, such as colour or a perm.


Colours that reflect red, orange, or yellow.


A growth pattern that results in circular hair growth. Generally found in the crown.

widow's peak

A growth pattern at the front hairline that results in a pointed hairline and a strong directional hair fall.

zone 1

The first ½-inch to ¾-inches of hair growth.


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Hair Colour for Hairstylists: Level 2 Copyright © 2021 by Arden Magtiza is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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