The reasons bridesmaids dress the same is REALLY weird
Like many traditions, we tend to obey them without really knowing why.
If you've ever wondered why bridesmaids traditionally wear the same/very similar dresses, you're about to wish you never wondered.
Apparently, the tradition stems from Ancient Roman weddings, in which not only the bridemaids but also the bride would all dress alike.
This was so that the bridesmaids would act as a decoy, and that the altar would be populated with undistinguishable ladies, according to Mental Floss.
The site says:
"In the early days of the ritual we recognize today as the wedding, brides had a lot more than floral arrangements to worry about. Any glad tidings had the potential to attract evil spirits, for one thing—and then there were all the would-be grooms the bride had turned away."
So basically, in order to protect the bride from any demons or vengeful exes, the ladies would dress the same.
If they could confuse the unwanteds for so long as it took the couple to say their vows, it was a win for the goodies.
This fear petered out in the Victorian era, when brides started to dress more extravagantly than their bridesmaids.
But unlucky for many bridesmaids, their uniform stuck.