Human hair fades.
The best point of human hair is its naturalness, but it cannot avoid fading.
In several months, the hair color gradually fades into reddish brown
If you leave it and continue to use wig, the boundary between your own hair and one of the wig will be clear and it will easily come out “a wig”, so dye it before the boundary becomes conspicuous.
≫Here is “hair coloring”.
Artificial hair is made of synthetic fibers, so it won’t fade.
It doesn’t absorb water, either.