White is safe, but not the only way to go. With your foreshortened walls and singular light source, the white walls will be largely in shadow, and the envelope will lack definition, and can appear dingy in parts of the room. Using saturated colour on the walls (though not dark shades) and keeping the ceilings white provides sharper distinction and interest, and actually makes the ceilings appear to be airier by contrast. I think jewel tones accomplish this best, and personally prefer to use bright oranges and yellows in these spaces for a sunnier effect. I have tries to choose pics below that most closely resemble your angles and light source, so you can compare all-white, earth tone and jewel shade options.
On a secondary note, choosing flooring with a glossy surface will be of help in bouncing light into the recesses of the room.