Color and shape
Start with white, ivory, light oak, or ash. The slab should be flush or a single flat panel. Heavy molding and dark walnut belong to other styles. Black can show up as a lever or a thin track, not as every door on the floor. If you want one darker door, keep it matte and put it where you mean to mark a room, such as a bedroom off a white hall.
Glass helps the light the style depends on. A tall frosted lite in a pale door brings a windowless hall to life without turning the bedroom into a display. Skip divided-lite grids unless the rest of the house is already cottage, not Scandinavian.
Openings that keep the floor clear
Small rooms are common in this kind of plan, so the door should not steal floor. A pocket door is the cleanest way to get the slab out of a bath or a laundry. A single swing is right when you have the arc and you want a simple, tight close. Barn door hardware is optional and should stay visually thin. A heavy black strap kit on a pale oak door is a farmhouse gesture, not a Scandinavian one.
Closets can be bifold or bypass in the same pale finish as the room doors. A different closet style is what makes a hall look unfinished.
Order one palette
Match height, finish, and hinge color across the rooms you can see in one walk. 80 inches is the normal height. Go to 96 only when the ceilings and the other doors already support it. Order the set in one batch so the white is the same white. Hardware stays in one metal: matte black or satin nickel, not both.
Flat casing painted with the wall is enough trim. If you want even less, look at frameless doors, but only where the jamb can be built for them. They are not a cover-up for a crooked old frame.