Is it permissible to dye hair colors such as blue and red, and is that considered imitation?

It is permissible for a woman to dye her hair with colors other than black, as long as it does not involve imitation of disbelieving women. The Prophet, peace and blessings be upon him, forbade changing gray hair with black dye. As for other colors, the basic principle is permissibility, unless it is in the style of disbelieving or immoral women.