The headlamp standards (both the US standard and the rest-of-the-world standard) allow a range of performance. The bottom of the standard isn't tightened up very often at all. If you look around at discount stores, you can still find plain tungsten (non-halogen) sealed beams. They're legal, they meet the minimum requirements, but they're awful to drive behind because they don't put out much light. With all these "whiter light" bulbs and sealed beams, the makers take advantage of the allowed range of performance; they add the blue-tinted glass so they can make marketeering claims about so-called "whiter" light (that word "whiter" doesn't mean anything real). The blue glass reduces the amount of light reaching the road, and to get the minimum allowable amount of light thru the light-blocking blue glass they have to overdrive the filament which causes short life...
...but (to answer your question directly) there are only two kinds of headlights as far as the law is concerned: compliant (legal) and noncompliant (illegal). Nobody gets a gold star on the Federal fridge for headlights that are better than the law says they minimally have to be. That's left up to market forces, and the marketers of "whiter light" headlights seem to have made a correct decision that people will pay a lot of extra money for perceived/misinformed "improvements" even if the reality is that they're worse off.
