Marriage & Weddings

Am I in the wrong during our wedding planning?

So me and my fiancé get married in one month. When we first started planning she wanted me to have a day to go choose outfits for her brothers and dad she has 3 brothers. I told her I don’t mind what color of suit they wear as long is it’s our color which was blush. But she insisted on me going to get suits fitted with them I go To a suit place with them. We get there and I tell them I want to give you guys the liberty to choose what they want in color as long as the shirt is white, tie is blush and hanker-chief if blush to match what my groomsmen are wearing which is the same except a blue suit. Her dad really likes a grey suit so I told them you guys should get a different shade of grey to match your dad. So they agree. We’ll she starts telling me I put no effort and thought into what they wear because I gave them the liberty she gets upset. So she tells me the only little brother I have needs to wear grey. I agree to it to make her happy but when it comes down to choosing my little brother I chose navy blue for him I instead of grey (like my grooms men but a different shade). I chose this without her because I didn’t see fit for my little brother to match with her family as it makes no sense because he is my brother. I understand I went behind her back and made this decision on my own but I didn’t want my little brother to match with her dad and brothers. now she wants to cancel the wedding unless I change my brothers suit to grey. She is giving me a ultimatum and I want to know who is in the wrong. She is saying that I don’t care about her brothers and I only care about my little brother and says that I am wrong for doing this behind her back.
Am I in the wrong during our wedding planning?
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