A color block “frame” transforms a door opening.
It’s fascinating to see the way paint can be used to create visual effects in rooms. A painted-on headboard in a bedroom comes immediately to mind. There also are trompe l’oeil walls with perspective that puts depth of space in narrow quarters. Recently I found a photo [top] of a doorway widened by dark painted trim that creates a portal, expanding the opening well beyond its narrow dimensions. In this example, the deep blue used inside the archway replaces the need for casing. And while it has a slightly eccentric look, it might well be applicable to an open plan home where walls meet awkwardly and paint color transitions can be perplexing.