White Dress???

Me and my cousin are planning to renew out wedding vows together after 5 years. We got married within a month of each other last year. We are both researching things now and decided to start early in order to make sure we both get what we want. The thing is ive been reading other posts and some say not to wear a white dress. Why is this? my cous had a better wedding than me with a proper wedding dress but some plans fell through at the last moment so it wasnt how she wanted it. I had a quick cheap wedding and although i had a ivory dress it was plain and for my renewal i would like to wear a big white wedding dress with all the trimings. Do people think this would be ok? my cous was planning to wear her wedding dress.