For a realistic-looking wig that has consistent colour, all these ponytails must be processed and then dyed the same shade. It is critical for each ponytail to absorb dyes at the same rate in order to create a wig that is one natural-looking colour. Grey hair and some chemically treated or permanently coloured hair does not absorb dye at the same rate as other types of hair. It is much harder to colour and, once coloured, fades more quickly.