If the dye being used is a deposit-only color, which is a product that adds color to the hair instead of removing color, the hair may be immediately dyed again, assuming that the hair is strong and healthy. If someone wants his or her hair to be lighter, such as by using a product that removes color, he or she should wait 2 weeks.
When hair is dry and brittle, it needs to be treated for this condition before coloring is performed again. A hot oil treatment or deep conditioning treatment can help restore the hair to a healthy state. For drastic color changes, it is recommended to see a stylist, especially for a color change that requires a color remover and a deposit-only color.