Coors Light, the "Silver Bullet", is a 4.2% abv beer first brewed in 1978 as a low calorie beer. It is Coors' top selling brand and the third-best selling beer in the United States. It has won several medals for "American-Style Light Beer" at the Great American Beer Festival and is the official beer sponsor of the NFL and the NFL Network. In 2006, a "frost brew liner", referring to the "Frost Brewed" branding, was introduced. The nickname "Silver Bullet" originated at the University of California Alumni Association summer family camp, The Lair of the Golden Bear, where staff members coined the casual reference to the iconic slender silver cans. The previous marketing campaign mentioned how Coors Light was frost brewed with a frost brewed liner and then shipped via refrigerated rail cars and trucks. The current campaign is a bottle that has mountains that are blue when the beer is in proper drinking temperature. The name was then immortalized when one of the former members of the camp staff used it as a marketing campaign and the name has stuck ever since. Coors Light puts on major promotions at Halloween, including the "Beer Wolf" and plugs by Wyatt Thomas, tying in with the Silver Bullet theme. Coors Light bottles feature a cold temperature sensitive label using Chromazone ink. When the mountains on the label turn blue, the beer is at optimal drinking temperature.