For best results to achieve 4D on uncolored hair apply 4N (Chestnut). If applied on 1N (Black), 2N (Brown), 3N (Dark Chestnut), the color result will be very dark chestnut.
If applied on 5N, 6N, 7N, the color result will be Light to Light Chestnut. The same rules will apply if used on 4M, 4R, 4C.
To cover grey hair with 4D, it is essential to mix appropriate quantity of 4N (Chestnut) - Refer to 4N (Chestnut).