Are you going for standard height worktops? If so, I think it will be fine as the units will be just over a 1/3 of the wall height (things on walls seem to work better when in 1/3s or 2/3rds rather than splitting a wall in half). I would either paint the walls and ceilings the same colour or just go a shade or 2 lighter on the ceiling than the walls so you're not creating contrast. I've found this kitchen which I'm guessing is a similar height https://www.houzz.co.uk/magazine/kitchen-tour-modern-rustic-style-in-a-country-cottage-kitchen-stsetivw-vs~87744878

After having seen the style and look you like, although we spoke about dark cabinets initially, with the floor you have chosen which would compliment any style, how about considering a natural wood like worktop? If you would like a light, and airy look and feel to the kitchen, neutral coloured cabinets would suit the look of your kitchen, paired with a slightly darker splashback to add that luxe feel back to the kitchen. This combination of a darker splashback, with wood and then lighter cabinets would also work well with your accent gold bar stools in the first image you showed. Keeping the foundation of your kitchen balanced and adding accessories such as gold bar stools and some decorative elements to give it that sparkle and glint that you like! (featured here is our petrol blue splashback panel, however I feel our blueberry panel would also work really well with this combination)

If you’re looking for dark blues, look at Craig and Rose’s Payne’s Grey. Despite the name it is actually the most beautiful shade of deep blue with a hint of grey. I spent months agonising over blues but then got fed up in lockdown and got the Payne’s Grey, despite worrying that it would be too grey for such a dark corner. it is the perfect colour, and I’m looking forward to using it on walls elsewhere. It’s also usually cheaper than F&B and similar if not better quality.

Dulux light and space paint are coloured already with special light reflecting articles. The paints are all light colours.