Learn French: Ce dont j'ai besoin, c'est d'une coloration, d'un soin et d'un brushing. - What I need is a coloring, a treatment, and a blow-dry.

In French, the prepositions à, de, and en must be repeated before every noun in a series. Because the expression is avoir besoin de (to need), the preposition de (contracted to d' before a vowel sound) must appear before the coloring, the treatment, and the blow-dry. You cannot drop the preposition for the second and third items like we do in English.

Why is there a d' right after c'est in c'est d'une coloration? Couldn't we just say c'est une coloration?

When you emphasize a sentence using Ce dont... c'est..., the preposition de from the verb phrase (avoir besoin de) is typically repeated after c'est. It acts as a logical bridge showing that the items in the list are exactly what the verb is demanding.

Why does this sentence start with Ce dont instead of Ce que?

The relative pronoun dont replaces the object of the preposition de. Since the verb phrase is avoir besoin de, you must use dont to express "what I need" (literally "that of which I have need"). If the verb didn't require de, like vouloir (to want), you would use que: Ce que je veux.