Temperature-sensing dyes used to be too costly for food and beverage packaging, but the economics changed with the cold activated bottle from Coors Brewing Co., Golden, CO.

Thermochromatic ink changes the mountains pictured on Coors Light labels from white (top) to blue (bottom) as the beer chills. Source: Coors Brewing Co.

A dye-based thermochromatic ink-impregnated in the mountains on the label of Coors Light bottles-begins turning from white to blue as the beer’s temperature drops from 48