Yes, human hair wigs can be dyed, just like natural hair. However, it's important to note that not all wigs are created equal, and the quality of the hair will play a significant role in the outcome of the colour.
Human hair wigs and human hair toppers will be able to be coloured in many ways. However, if your wig or topper is made with low-quality human hair, it may not hold the dye as well, or the hair may be damaged by the chemicals in the dye.