subway tile + open shelves (wood tones warm up grays). dark grout, gray floor tile For kitchen, lighten cabinets to match open shelves tones, add white subway tile w grey grout and keep grey paint on wall. Consider wood tile instead of hardwood floor.
Wood floors/ transition to tile in shower image of a refurbishment in Buckinghamshire, posted by Interior Therapy, has been saved more than times by Houzz users. The classic but modern space features grey tiles and a personal typography poster on the wall