The usual developing time of hair dye is 30 minutes and it ensures saturated colour result. For lighter shades and in case of stubborn grey hairs, you may extend the time up to 45 minutes in order to obtain more intense colour and even hair coverage.
When rinsing your hair from the dye, it has the properties of a shampoo. Therefore it is not necessary to use a shampoo. After rinsing the hair colour, apply the restoring conditioner to protect and fix the colour.
No, KOLORA does not weaken hair : the hair colour formula was developed to make the hair soft, smooth and shiny.