In many cultures and traditions, red is usually associated with festivals and celebrations, so it may be appropriate to wear red at my brother's wedding.

However, whether it is suitable to wear red clothes depends on the wedding style, personal preference and the bride's opinion. If the overall style of the wedding is more formal, or the bride wants the guests to wear more formal clothes, then wearing red clothes may be considered too casual.

Therefore, it is best to consult the bride or groom before attending the wedding to determine whether it is suitable to wear red clothes. If you are not sure, it is also a good choice to choose other colors or wear formal clothes, so as to avoid unnecessary attention or conflict.