This celebrates the appearance in India of an incarnation of Lord Krishna in 1486. It is a spring festival and is celebrated in Hindu temples.
In India, it is customary to throw powdered colours and water at everyone, even strangers. You can imagine the mess if this is done indoors.
This aspect of the festival has now appeared in the Toronto area at relatively expensive parties. If interested, for March 16 see: www.kcgrouponline.com . It is in Mississauga and costs $35.
In nearby Milton, it’s only $20. See: http://toronto.kijiji.ca/c-community-events-Rang-2014-Holi-Celebrations-in-Milton-W0QQAdIdZ562615466
A cheaper alternative has been taking place at Woodbine Park which is not religion based. In a few years, it might become a Toronto tradition.