Is it permissible to dye hair, provided the color is not black, and why is black forbidden to the exclusion of other colors? Does hair dye prevent water from reaching the hair during ablution?

There is an explicit prohibition against dyeing hair black, whereas dyeing it with colors other than black is commanded. The reason for the prohibition against dyeing hair black is devotional (ta’abbudiyyah), and a Muslim's duty is to submit to what has been revealed in the Sharia.