You can't see the red lens behind the rear tinted glass anyways.... It's just there because the bulb behind it lights up white....
No, the red lens it's there as a part of the originally certified fixture to meet a Federal regulation, because there is no RED replacement bulb, incandescent, halogen or LED, that is SAE/DOT certified for use with that fixture.
Really a DOT #?? come on now you know its aftermarket and most likely doesn't carry a DOT #. most anything you buy won't carry a DOT #...
Maybe
you buy aftermarket replacement lighting parts of unknown origin, but I won't risk my safety to products whose manufacturers won't certify them to meet relevant standards. I limit un-certified lighting to supplementary and auxiliary applications.
Every automotive replacement bulb from Sylvania, Bosch, or any other "real" lighting manufacturer has their name and either a DOT # on the envelope or the base, or a part number that references back to an SAE/DOT standard.
In the US, all legally required automotive lighting fixtures must have DOT/SAE numbers molded into them, usually on the lenses. If you go through the complete list of Element recalls, you'll find several aftermarket replacement lighting fixture products that have been recalled for removal as illegal (and the manufacturers fined). The fixture certification is based on the use of a specified SAE/DOT certified lamp type and color. To be legal, all replacement brake or headlamp "bulbs" must be the same type and color as the originally installed bulb, and SAE/DOT certified for the application. To date, only Sylvania and OSRAM have submitted replaceable LED "bulbs" for certification, not as replacements for existing incandescent bulbs, but in conjunction with fixtures designed specifically for us with them.
Future Honda models will eventually incorporate LED brake and/or other exterior lighting. My guess is that the 3rd brake lamp fixtures will be the first to be replaced by LED fixtures. When they do, to be sold in the US, their LED assemblies will have SAE/DOT numbers on them. It would be nice if they were certified as a direct replacement for the 03-10 fixtures, but I wouldn't count on it.