Final answer:
For extremely resistant canities hair, stylists may use a higher volume developer or pre-softening to ensure effective color absorption due to the tight cuticle layer and lack of melanin in such hair.
Step-by-step explanation:
Extremely resistant canities hair may require the stylist to use a higher volume developer or a pre-softening technique to open the cuticle layer before applying color. Canities is the technical term for gray or white hair that lacks melanin pigment. Due to a tighter cuticle layer and a lack of pigment, canities hair can be resistant to color absorption, thus requiring specific techniques to achieve desired coloring results. A pre-softening step involves applying a product to slightly swell the hair, which helps in better penetration of the color later on.
There are distinct hair coloring techniques that stylists might utilize for challenging cases of canities, including using a permanent type of color and ensuring adequate processing time. A professional stylist should understand the potential risks involved with using strong chemicals on the hair and take necessary precautions to protect the client's hair and scalp health. They may also recommend treatments and hair care routines to minimize damage and maintain the health of the hair.