CFR 14 Part 91.209 requires position lights and strobes to for the aircraft to
be operated at night...
 
position lights include a rearward visible white light ... not a strobe.

Hmmm.  Anti-collision lights (strobes) must be on if they are operable - day or night.  Strobes are white lights.  Whelen even provides a strobe box which fires a strobe taillight. 

 

It is more important to that the required lights are visible over the required angular range.  Some people bury the wing strobes (anti-collision) thus making them useless from the rear.  If the wing strobes stick out far enough so that one of them is always visible from the required rear angles for the white position light it should be ok.

 

Hmmm...