C4 Ultimate Energy Frost Collection

The Frost Collection from Nutrabolt, owner of preworkout brand C4, features what the company calls "a first-of-its-kind technology in the energy drink sector" that changes the can's color from silver to blue to let consumers know the beverage is cold and ready to drink. Offered in 16-ounce cans, the collection includes three flavors: Frost Bitten Citrus, Tropical Tundra Frost and Cherry Bomb Frost. All products in the line contain the same 300 milligrams of caffeine plus TeaCrine and Dynamine found in other C4 Ultimate Energy drinks, and have zero grams of sugar and no synthetic dyes.