An application device for applying hair-coloring composition, comprising a device body, comprising a first reservoir comprising a first piston; the first reservoir configured to receive a first part of a hair-coloring composition; a second reservoir comprising a second piston; the second reservoir configured to receive a second part of a hair-coloring composition; and a dispensing mechanism associated with the first piston and with the second piston: the dispensing mechanism configured to sealingly move the first piston inside the first reservoir and the second piston inside the second reservoir; and an application cap, comprising a mixing mechanism; and a plurality of projecting tines: wherein the application cap is configured for reversible-connection with the device body such that, when the application cap is connected with the device body, the first reservoir and the second reservoir are sealed from the outside except channels of the plurality of projecting tines which are in fluid communication with the first reservoir and the second reservoir, through the mixing mechanism; and wherein the dispensing mechanism is configured, when activated, to move the first piston and the second piston towards the plurality of projecting tines thereby mixing the first part of the hair-coloring composition with the second part of the hair-coloring composition to form a mixed hair-coloring composition to be dispensed through the plurality of projecting tines.

The present invention relates to a device and method for selectively bleaching or dyeing a plurality of locks of hair. The device basically comprises a selector comb for selecting the locks to be treated from a portion of hair, and a container provided with at least one compartment that can internally house at least one liquid or pasty product for dyeing or bleaching. The selector comb is partially introduced inside the container and is movable inside and along same, being coupled thereto such that in an operating position of the device, the movement of the comb takes place, causing the gradual introduction of an increasingly longer portion of the locks selected by the comb inside the container at the same time as the gradual opening and communication of the inside of the compartment with the portion of the locks introduced therein, said portion being exposed to the liquid or pasty product.