two-tone hair
A specific type of multicolored hair where a character or person's hair consists of two distinct colors.
The division between the two colors may be an immediate change from one to the other or it may be done in a gradient, in which case the gradient hair tag would also apply.
If the color division is made approximatively at the middle of the head, it's also split-color hair.
See also:
This tag implicates multicolored_hair (learn more).