73 Challenger taillight question

[Super-G]

OK so I have a 73 Challenger. The car has 4 lights in the rear. 2 outside lights which serve as brake, turn signal, and running lights. My 2 inside lights have a red lens on the outside and a white lens on the inside. The white lens is obviously for back up lights. But the light socket that's installed is for a single bulb only. I have no red lights on the 2 inside taillights at all. I'm thinking that this can't be correct. I would think at night I should have 4 red running lights.

Can anyone enlighten me?

 

[burdar]

The inner lenses are just for reverse. It would be a neat custom touch to convert all four to regular tail lights but the lenses aren't interchangeable.

 

[Adrian Worman]

It could be done fairly easily, but you would have to fabricate a reflective shield inside the light cluster to stop any bleeding of light from one colour to another.
In England we can't have a red indicator on any car made after 1967, so we regularly adapt tail lights to overcome this, a 72 on car is an easy conversion because the inner light cluster only does the reversing lights.