Can you dye your mustache with normal hair dye?

Depending on your hair type, it may take a little longer to dye than the hair on your head. Moustache and beard hair is usually coarser and takes longer to absorb the color. It will not hurt anything. Some hair dyes have ammonia in them and the fumes can get fairly intense under your nose. Having done it myself, I would recommend getting coloring made for a moustache and beard such as "Just for Men."