Final answer:
To color predominantly grey hair, use a dye designed for grey coverage with a higher developer volume and discuss realistic color outcomes and after-color care with the client.
Step-by-step explanation:
If your client has predominantly grey hair (canities), and they show you the color they would like on a color chart, the first step is to assess the condition of their hair and the percentage of grey coverage needed. It is important to understand that grey hair lacks pigment and can be more resistant to color because the follicle may have a tighter cuticle layer.
Therefore, color selection should involve choosing a dye that is specifically designed for grey coverage, which often contains a higher volume of developer to open up the cuticle and longer processing times.
Performing a patch test is always advised to ensure no adverse reactions to the products. Also, discussing realistic color outcomes with your client is crucial since the natural base color can affect how the dye will look on grey hair, and it might not always be possible to achieve the exact shade on the color chart.
Professional advice should involve options for adding highlights or lowlights, opting for a semi-permanent color for a softer blend, or a permanent dye for fuller coverage. Lastly, after-color care recommendations are essential to maintain hair health and color vibrancy.