If you like the reduced volume of the Parlor guitar (so as not to wake the neighbors), You might enjoy Flatwound strings, for purer tones at low volumes. Roundwound strings produce a fair amount of "noisy" overtones which can make notes difficult to identify at lower volumes. Flats don't.
But beware, most flats are "coated". The coating will wear off and the volume and "presence" will drop suddenly and substantially when this happens.
My favs are Thomastiks. I've probably said enough about them in my other answer here.
So if you're bold and curious, try a $10 set of D'Addario Chromes, play it until the coating wears off to get a sense of the spectrum of tones flats can give you.