My therapist has asked me to wear colorful hijabs and abayas as she says that it is proved from studies that colorful clothes will help uplift mood and make one feel happy and joyful and she says that it will help me. But wont that make me look attractive and that defies the purpose of covering myself. So im not sure what i should do?
You must not listen to her as this indeed defies the purpose of hijab. You can wear all the colorful and attractive clothes in front of your mahrams and in front of other women.
You should change your therapist and choose a practicing Muslimah.