Washi tape to the rescue (again): We like this idea for adding a citron-colored graphic note to an otherwise austere white room.

Above: The bedroom in the home of the Mulhouse family in France; it's one of many rooms decorated with a few strips of washi tape. Photograph by Julien Fernandez.

Above: All you need to recreate the look is a measuring tape, a steady hand, a pencil to draw a light guiding line on the wall, and a few rolls of tape, such as Dotted Yellow Washi Tape for $8.25 from Pretty Tape on Etsy or the Wide and Narrow Light Yellow Washi Tape for $7 from Cute Tape.