Change hair colour within the natural range with a one hour casting time
Casting Time 1 hour
Components V, S, M (Various soaps & water)
Range Touch
Target willing non-bald humanoid creature touched
Duration instantaneous
Saving Throw Fortitude negates (harmless); Spell Resistance yes (harmless)
By taking one hour washing the hair of the target with soaps and water and massaging the scalp to rearrange their natural energies, you can change their hair colour to a different one.
The colour designated must be one that is natural to the species of the creature. For example, you can turn a blonde human woman into a redhead, but you cannot make their hair turn green unless there are green-haired humans in the setting. For Aran, this leaves a relatively wide array of colour options.
The hair retains its new colour even when washed, though new growth will be in the targets natural hair colour, which means it takes a month or so before roots start to show.