Florina can dye your hair for 1000 Dosh, and she lives in her cottage in the West Grassy Plains .
For a full body makeover visit the beautician in the Forest Shrine in Origin Island(DLC), which costs 150,000 dosh.
When you see Florina, you have the options to change your hair color and style. Your hair options are the ones from the beginning of the game. If you get the DLC mid-way, you have different hair options to choose from. (You can only change your hair with the hair dying bliss bonus.)
Florina has a magical flower called Lippy Lippes. If you get the clothes dying bliss bonus, you can have Lippy Lippes dye dyable clothes for you.