Dont be sorry, I'm very honored to be your personal interior designer (I prefer not to be your personal nightmare! :D) Grey is always a good choice, especially on one single wall, but has to be choose in a sustained tone, strong, to express its full beauty. A charcoal gray behind white furniture gives a clear character to a space. Very nice floor! If you are hesitant, keep first white walls, but the problem is that when work is finished, it is it difficult to restart. Sometimes you have to dare and often the result is really wonderful.