The Boutique Hair Event is a 7 day limited time event that will unlock a new set of hairstyles.
To complete the Event you need to complete a Fashion collection within seven days.
When you start this Event any current Fashion collection will be reset to zero.
To complete the Event your Sim(s) will need the Fashion Studio item from the Promotions R Us Store. This costs 2500 Simoleans and will allow your Sims to have the Fashion Designing Hobby.