It's the floor colour that's the main problem, neither one thing nor the other, and certainly wrong with the benchtop. Leave the wall tiles if you like that sort of thing and find a way of covering the floor probably with laminate planks on an underlay. We have a European Birch golden coloured timber floor but softer grey splashback and it looks fine. It's not an award winner but the floor and cabinet carcases had been there twenty years and it was affordable. Don't even think about painting the floor or putting down mats but a clear plastic runner in front of the sink works well for us.

I went vertical so tall. Helps to raise height. It will also match your 300 floor tiles I have silver grout with antique white tiles. It’s a personal choice you can’t go wrong either way.

The size of floor tile: 300 x 300 mm and the size of wall tile: 300 x 600mm The floor tile and wall tile do not align at all. It looks unprofessional. Should the tiler redo the job? Thanks for your advice.

If the hexagon tiles are to be the feature then the wall tiles should not draw attention to themselves. I would go with stacked horizontal as this will make the small room seem wider and it will be a simple grout pattern that won't try and compete with the hexagon mosaic. For small bathrooms understated and simple always looks cleaner. Best of luck, Dr Retro of Dr Retro House Calls