I believe the reason the tiles work well with the cabinetry is because the tile is lite in color and flat, its not rustic unlike most terracotta. The expensive cabinets work fine with the floors because of the smooth finish. The floor here is the focal point of this room. The Interior Designer or whoever did this room, did a very nice job, keeping it very simple.

those tiles from the 1800s are encaustic... the color goes all the way through. ceramic tiles are red in the middle and have just a relatively thin layer of color and glaze. porcelain tiles do have a color matched center (look at the edges to tell) but i'm not certain that all of the pattern goes through. at least it would wear off and turn the main color, not red.

Something to take into cosideration would be the amount of light you have coming into the bathroom. Obviously if you have considerable light and air the tile shade wouldn't be too much of an issue. On the other hand if the room is small and not very light filled, then the lighter shades would be preferable giving the illusion of making the room appear bigger and lighter.

I wouldn't do skirtings . I'd do the floor tile for '1 tile' up the wall ( assume they are 200 x 200 or 300 x 300 -- cut them if 400 or 600 ) . Personally , I'd probably even do the 'silver' tiled areas in that 1 height darker tile too , as it would make the whole room look more 'level' , but thats up to you and your tiler .