(Applied on Dark Chestnut - colour remains the same and covers grey hair)
3N can be used on the following colours to achieve a dark tone colour:
4N - 5N - 6N - 7N - 4D - 5D - 7D - 4M - 5M - 7M - 4R - 7R - 7C
3N - Dark Chestnut with 5% Grey hair
If grey hair is all over the head, you can use 4D, this will create highlights on the grey hair and Dark Chestnut on the rest of the hair. On more than 5% you must use this formula.
3N - Dark Chestnut with 10% - 20% grey hair
Mix 25ml of 3N, 35ml of 4D, 60 ml of glycol to get a Dark Golden Chestnut.
3N - Dark Chestnut with 30% - 50% grey hair
Mix 3Oml of 3N, 3Oml of 4D, 60ml of glycol to get a Dark Golden Chestnut.
3N - Dark Chestnut with 60% - 100% grey hair Mix 45ml of 3N, 15ml of 4D, 60ml of glycol to get a Dark Golden Chestnut.
This formula will apply for 3N Dark Chestnut to be mixed with 4D as above or 4M (Mahogany Chestnut), 4R (Copper Chestnut) and 4C (Ash Chestnut).