Final answer:
Lighteners are needed when clients want a dramatic lift or when their hair is previously color treated. Lighteners are hair products that help remove or lighten the natural color or previous artificial color.
Step-by-step explanation:
Lighteners are needed when clients want a dramatic lift or when their hair is previously color treated. Lighteners are hair products that help remove or lighten the natural color or previous artificial color. They are often used before applying a new color or when a client wants to achieve a lighter shade.