It all depends on how much money you would like to spend. As your lounge is dark and your stools and bookcase are also dark I think white chairs would be fine, but then I would change the stools as well and take some white down to the lounge area. However you can buy stretchy covers for this style of chair for around $10 and there is quite a variety, so I would look on line for those to see if you like any of them as that would be a very easy fix.

Anything with colour would be a bonus in your place IMO . So grab 4 cushions in the same blue , and 4 with say lighter blue and white stripes or chevrons ( wiggly things haha ) -- that references the dining chairs and brings in a lighter blue . The cushions are for the couch btw , in case you hadn't clicked haha . Maybe a rug . Definitely a larger artwork with the dark and lighter and maybe a mid blue too , a splash of yellow and orange and grey in places . Suddenly , its gone from drab to okay . One thing I do slightly worry about though is the table top colour -- its got olive green drab tones to the brown IMO , and will probably make both the top , and the chairs , look plain and almost muddy in vibe -- a Japanese Black stain on the table top ( similar to your island front ) would look better with blue chairs in my mind .

Your kitchen looks amazing. I would go for all black chairs, they reference the rest of the kitchen. Any chair with wood introduces another type of timber which is tricky to match and takes away from the minimalist palette you have.

That should be Kave. Autocorrect! Also have a look at Temple and Webster. A good search term is “carver fabric dining chairs”