A new alternative to hair dye is said to be in the very early research stage. From the article:
These pigments restored the hair to its original colour, from the white or grey it had become. This took place no matter what the hair colour was to begin with.
The drug, known only as K(D)PT, increased pigmentation when it was applied to hairs gleaned from women undergoing facelifts. However, it was effective only when the strands had been pre-treated to mimic the damage found in conditions that cause hair loss, including some forms of alopecia. In such conditions, hair that grows back is often white.
Full article at UK’s Daily Mail: No, it’s not a pigment of your imagination: Breakthrough drug can restore white hair to its original colour
This is an interesting news release. If you’re coloring your hair, you’re not going to be able to put the dye away just yet, but we’ll see what comes of this in the future.