Am I the asshole??

5

AITA for 'trying to upstage' my sister at her wedding

  Okay so despite having some spats recently I (26F) was recently invited to attend my sister's (31F) wedding. Now I'm not part of the bridal party or anything, I honestly don't think I'd want to be but just going as a guest. The rules my sister laid out were that it can't be white and it has to be a more formal type of dress, which I didn't mind and agreed to the rules. I had the perfect dress in mind which was one I wore to a friends wedding about a year ago which I had still held onto. For information the dress is a floor length silverish dress with a leaf-like design, and not too flashy or anything.
  So deciding it was better than spending more euro on a new dress I opted to wear it. So jumping to the day of the wedding I show up in my dress with my boyfriend. Everything seems fine up until the reception afterwards where my sister acts somewhat cold to me after I come up and congratulate her and her husband. My sister tells me that she doesn't approve of my dress and that it would be best if I left. I asked her what was wrong about it as it fit both requirements she had set for the dresses worn. She told me that it looked as if I was attempting to upstage her at her own wedding with my dress of choice.
  Not wanting to cause a scene my BF and I opted to not argue and leave. On the way out my parents asked where we were going and I told them the situation. They seemed conflicted with my mother agreeing that it looked like I was trying to be too showy at the wedding where my father agreed with me that it wasn't too fancy of a dress and my sister just seemed jealous. But now I'm wondering if I am TA in this situation and need to apologize to my sister for it.
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                              EDIT
Since everyone assumes that I am from a western family. My father is Turkish and mother is Belgian. This was a traditional Turkish wedding where the bride wears Reds, limited whites, and golds. Traditionally in Turkish weddings you wear formal clothing. Everyone else was wearing floor length dresses and men in tuxedos.