Human hair wigs can be dyed .But synthetic can’t.
If you want to dye hair we suggest you go to salons because dying needs a professional skills.
Usually when we dye hair we need to bleach it then color it .
From light color dye it to dark color is easy but if dye it from dark color to light is very hard.
The bleach time and dyeing time is very important and Kindly ask yours hair stylist to dye it for you if you want to dye hair or wigs.
To be honest ,dying hair can damage to hair. We don’t suggest you dye your own hair . It will let your hair looks no nutrition including dry .
If you want a colored wig, we suggest you buy a colored wigs directly. Hair market have many different kinds of colored wigs .