Formulation should include knowing the

• natural hair color
• target hair color
• level and tone
• contributing pigment
• percentage of grey
• type of hair color product.

Process/Skill Questions:

• What techniques could be of assistance in selecting the client's desired hair color?
• Why is the contributing pigment important?
• How do undertone and level impact formulation choice?
• What causes brassiness and how does one neutralize it using the color wheel?