My research found no evidence of this holiday being originated as a protest to war or any kind of conflict.
Rather, I found this day to be a stellar event. It seems some of you out there fear that aliens from outer space consider earthlings to be too hostile. As a result, they have yet to visit or make contact with us. So, some of you decided to promote world peace by establishing Wear Purple for Peace Day, wearing purple apparently encourages aliens to contact us.
I’m not sure if it’s because purple is a peaceful color or a favorite color among extraterrestrials. Whichever way you interpret the holiday, there’s no harm in promoting peace with the color purple.