The Washington Post (free registration) explains why bad things – like aromas reeking of skunk – happen when light meets beer.
It also explains how Miller gets by with using colorless glass:
Chemical trickery, that’s how. Instead of using actual hops for bittering the beer, Miller uses a chemically modified form of hops’ alpha acids known by several brand names, among them Tetrahop Gold. It does not produce 3-methyl-2-butene-1-thiol when struck by light, but according to the Ghent chemists, it can still produce rotten-egg odors. Uncolored bottles are cheaper than colored ones, however, so Miller’s fiscal folks apparently prevailed over their flavor mavens.
As you can see this is an educational but amusing read.