I've heard so much about this festival and always found it a very interesting and beautiful tradition. Here in Ecuador, the Pawkar Raymi (Flowering festival) is very similar, though no color throwing. But there are flowers and color everywhere, and foam and water and flower are thrown at everyone, all the time. It's a beautiful thing and Lily enjoyed it thoroughly this year, as there was a huge foam cannon:

Sorry to read about your anaphylactic shock. Glad it wasn't fatal, and I hope that you recover quickly and completely!