The amount of light. The kind of light. The number of different "kinds" of light, all told, all together. Where the light gets projected. Whether the light is dimmable. ALL these questions are so important that they make the difference between a prize winner and an also-ran (at the back of the pack!). The other questions you asked dealt with surfaces and furniture. In a tiny space you gain little by changing the shape of the furniture. In any space that relies on electricity to light the space (no natural light from the sun or from an alleyway), you must think about the theatrical effect of lighting. To keep it simple: get something that uses high - CRI tube fluorescents, something else that is LED's, and something else that "bulbs". Three different kinds of light. Shine them near the wall not from the middle of the space and not into the middle. Consult more before acting on this. go to the lighting forum, read a bit, and then post about your goal: Something like this: "design light plan for manmade light in narrow bathroom" Here is a link that might be useful: lighting forum

The inpiration is lovely, but for your space I'd go for lighter tile. We just finished a small basement bath and even with lighter tile it seems small. Euro style vanity is a great idea,

The best small bathrooms & powder rooms I've seen are the ones in which everything really ties together, no quirky odd elements or tangents, & it seems like you can "get away with" more in a small space than in a big one. You can be more starkly modern, more decadently Deco, more specialized & individual. You can put down a floor that looks like water (don't know how that's done, but it's cool), you can use a bright orange 70's theme, things you'd never do in a bigger space. I saw one below-the-stairs powder room that was done in a Victorian theme, very busy wallpaper in warm gold/brown/burgundy tones, dark hardware, dark cabinetry, etc. It was like a perfect little gem. & it wasn't exhausting to the eye because of course nobody spent much time there.

Certainly ask the kids for suggestions, but in the meantime, I would concentrate your search on warmer colors that will compliment the warm sand color of the tile. I have a feeling something in the same family as the former yellowish cream color will probably be your best bet, although I could see a warmer green (with more yellow than blue) working in there. If you don't mind a dark color in a small space, a warm chocolate brown or a deep plum could look nice as well, although I have a feeling it might be overwhelming given that there are no windows.