S.H.
Girls. They are like this.
NO biggie.
My daughter did the same thing at that age.
They are changing and developing and getting to know themselves... their likes/dislikes/their sense of "evaluating" themselves and others. Par for the course.
My daughter even like to change panties like 4 times a day, and outfits.
For me, it was no big deal if her clothes didn't match... lots of kids in preschool were that way too. Tis' the age.
They "need" to "master" different concepts and changes in themselves... its fine. No harm if their clothes does not match perfectly. I see LOTS of kids that way.
The thing is, is that they learn about color... about what their clothing taste is etc.
For example: my sister (Aunty) used to try and MAKE my daughter wear "preppy" styled clothing... and that is what she would buy my daughter. BUT... my daughter out and out hated it and would get so upset when my Sister tried to make her wear what she bought. I had to explain to Aunty... that "Sally has her own style... she knows what she likes and she likes to make up her own outfits... I think she has great taste..."
My daughter felt SO proud of herself whenever she put together her outfits... and she is now a 6 year old girl, who KNOWS herself, and knows what is classy appropriate clothing for a little girl, versus (as she calls it) "trashy girl outfits...." Which she learned all on her own. And as a Mom, I always discussed clothing or her tastes, and "how come you like that color with that outfit?" which are questions I would ask her so that she could BUILD a sense of "self" and her own values.... to this day, she is a VERY wise and articulate girl... who is great at "matching" clothes, now.
It came with time and per her age.
Don't worry... it's a phase and will pass. Your daughter will one day match clothes perfectly and be able too... but at this age, they are experimental and exploratory and NEED to try things out on their own.... with our guidance.. but if you try to make her wear certain things (as my daughter's Aunty did) it will just make them upset.
I just utilized that "phase" in my daughter to teach her about things- color, developing her own 'taste' and impressions about her world view... and I did not compare her to others. My girl even went through a phase at that age where she wanted to wear knee-high socks with her flip-flops. She looked like a clown, but she was SO SO proud of her clothing style, and she didn't care what other kids thought. So LOVED her outfit! AND she felt "good" about herself. SO that was fine.
My daughter is a great dresser today... and chooses her clothing so well. :)
Don't worry... it's just a phase... but instead of turning it into a "battle" seize the opportunity to use it as a "teaching" opportunity and a way to bond with her and enjoy the differences in "style" that all people have.
All the best,
Susan