1261: You are clouding the issue. You cannot operate under two different flight RULES at the same time.
You are either flying under INSTRUMENT Flight Rules (IFR) or VISUAL flight rules (VFR).
You may be operating in either Visual METEOROLOGICAL Conditions (VMC) or Instrument METEOROLOGICAL Conditions (IMC), and I think that is to what you refer in your example. If you are flying an ILS you are IFR (because you cannot fly by sole reference to instruments AND look out) but you may be VMC or IMC. If you are VFR you must be VMC.
At night with no IMC rating you must be VMC but you are operating under IFR.