Wear Purple for Peace Day is celebrated on May 16, 2017. It's a day to promote peace between us and any space aliens who might be lurking about. Obviously the unknown creator of Wear Purple for Peace Day thought that purple would be the one color to signalize aliens that humans are a peaceful species.
You should wear a purple ribbon or purple clothing to be part of Wear Purple for Peace Day. The color purple has always been considered a very special color as it is not often to be found in nature. It stands for creativity and supernatural powers. Wear Purple for Peace Day now adds one more expression: being peaceful. If you live in a peaceful country, count yourself lucky on this day.