When I installed my headlights, I made sure to buy ones that were DOT stamped, just to be safe. Last week, I replaced my rear bumper lights with some Depo smoked bumper lights, since one of the stock ones was damaged when my car was hit. The lights have a red bulb, so at night it is hard to tell the difference.

 

As far as I know, the rules are all about what color they show when turned on. Red is not allowed in the front AT ALL (only emergency vehicles). Clear lenses that light up amber in front should be OK. Clear lenses that light up red in back should be OK.

There's also rules about how many candlepower is allowed, how many forward lamps are allowed, stuff like that. And headlights have to have a certain beam shape in order to get DOT approval.