Walls: grey concrete-colored tile (not too dark, not too light):
Flooring: Ceramic faux-wood tile, seen at Alony.
The same tile will be used in the bedroom and continue into the bathroom.
A large, convenient, sink, that rests on the counter top.
The cabinet beneath the sink (including the counter top) will be formica in an interesting wood-like design. I think we found a bamboo-like texture which might work. I don't have a photo of it yet. Or alternatively, the cabinet could be any other solid color (cream, green...).
Shower with either transparent or translucent glass doors:
In the niche above the toilet, shelves can be installed.
The shelves or the wall behind them can be colorful (turquoise maybe).
The walls which are not covered by tile can either be painted a neutral whitish color, or a stronger color, or using a rough texture such as the grey in this wall:
There will be a large mirror above the sink, probably without a cabinet behind it.
There might be a small shelf (glass or indentation of the wall?) underneath the mirror, or not.