While The Sims has always been a socially aware game in terms of issues, the (Product) Red Event is more about raising awareness of the issue of AIDS and prevention than it is anything else - and despite that it has been nicely integrated into the game with a series of missions.
The goal is to complete as many of the missions - as a community - in order to unlock special Items and gifts.
During the (Product) Red Event, social Points (SP) have been changed to (P) Points - Product Red Points basically - the idea being to get the players to purchase SP / (P)P from the in-game store, since all of the proceeds from such purchases goes to (Red's) fight against AIDS.
So you can get yourself some PR themed Items, and while the Event is in force the Gems over your Sims heads as well as the SP are Red.