Dye Bleached HairQ: How long must I wait until I can dye my hair after I've bleached it?
A: That all depends on the condition of your hair after the bleaching process. Unless the hair is damaged by the bleaching process, you should be able to use a deposit-only color on the hair immediately following the bleaching. This is commonly done in a two-process color service, when the hair is to be taken from a darker color to one that is significantly lighter - the hair is lightened then a color toner is added to create the desired color.
If the hair does appear too dry or damaged after bleaching, you may need to perform a deep conditioning service on the hair to restore some moisture and protect the hair for the color application. Be careful to use only 10-volume developer or weaker in the color mix, as you should not need any additional lift to the color and want to make sure the color mix is as gentle as possible on the hair.
The hair bleaching process
How to deep condition hair
How to tell if you have damaged hair