That is probably because the fire magic I have is connected to the brooch I have pinned onto my clothes. With the brooch, I could switch between powers relating to the sun, moon and stars and that does reflect on the dress styles. For example this golden gown can let me use fire magic at will.

(She conjures up a fire ball to throw at an incoming leaf monster (not the one they were dealing with earlier) who is shambling right behind her back. It then bursts into flames, screaming in horror as it flails around.)