Changing Hairstyles

When we first create a Sim it pops up on the window that we can create a different hairstyle for each look. I dont know if I am misunderstanding it but I tried to change into each of outfits then go into change appearance and change the hairstyle but that specific hairstyle stays for all the outfits once I get out of the change appearance option. Is there a way to do this? Am I doing it wrong or did I just misunderstand. If there is a way, can someone please tell me and if there is not...it would be nice to add this option into the game! Thank you!!:womanhappy: