Well, there's nothing more American than Red, White and Blue, so try these beers for a truly festive fourth.
Red: It's hard to go wrong with Odell Brewing's Red Ale, but that beer can be hard to find in July (it's an early spring seasonal). So, Ska's Pinstripe Red is a suitable backup.
White: Sure, Avery's White Rascal is a Belgian white ale, but it was created and is brewed right here in the good old U.S. of A. Blue Moon is a good backup in the white category, or the blue, if need be.
Blue: Anything from the Oskar Blues Brewery in Longmont. If it's hot and you have a lot of ice, try Mama's Little Yella Pils. Otherwise, Dales Pale Ale makes the perfect companion to hotdogs and hamburgers. Blue Paddle Pilsner from New Belgium is a suitable backup.