For a more unusual twist, trumpet-shaped wooden bar stools (and matching bistro-height table) are an option. The shape is enhanced by the footrail that is only on one side which helps keep the profile slim. They’re great for a casual kitchen or bar area.
Because bar stools are a taller seating piece, they tend to be noticeable. A glossy modern stool or three can go a long way toward making an entire area feel more contemporary, if that is your aim.
For a color palette to be harmonious, there’s no need to match everything in an obvious way. These bar stools coordinate really well with the kitchen island and the whole décor in general. The seat is a combination of white and gray which are also the colors used throughout the room.
Another good example of simple design that fit in a variety of interior designs is that featured by Stool_One by Magis. Here you can see it displayed in a contemporary setting where it complements a large kitchen island.