Yeah, those are pretty dark and clunky. I might go for white or even a bright color, depending on other furnishings. Here are a few ideas. (I have the Bernhard in orange.)

https://www.ikea.com/us/en/search/products/?q=bar%20stools

Mine are fully upholstered( saves the counter top edge , swivel with no arms, wood legs. I love them. I spend much time at my counter here on my lap top. It took me 20 years to find them. When we moved in there were very country all oak rounded back stools that I never liked.

Yep, the black is jarring against the rest of your finishes. Here are some that may work:

1. https://www.wayfair.com/furniture/pdp/foundstone-coleman-bar-counter-stool-w001832261.html?piid=418473077%2C418473079

2. https://www.wayfair.com/furniture/pdp/alcott-hill-waco-265-bar-stool-w000108798.html?piid=1744687623

3. https://www.wayfair.com/furniture/pdp/george-oliver-birdsall-bar-counter-stool-w002154283.html?piid=1034623717%2C1034623737

4. https://www.wayfair.com/furniture/pdp/langley-street-alyssa-bar-counter-stool-lgly6058.html?piid=40538672%2C24100753

i really like the bar stools with the wood grain on the back to match the counter top

I like these. Swivel. Ideally I would prefer a quality leather look vinyl but it’s hard to find a swivel with a comfortable back height that’s not bulky and has a good quality faux leather...easy wipe down.

The one above has fabric choices.

I don't think they're terrible but bar stools are a great way to bring in some color and texture.

These from Ballard Designs are customizable.

https://www.ballarddesigns.com/harris-barstool-with-welt/furniture/dining-kitchen/barstools/360275?listIndex=17&uniqueId=360275

Do you actually have enough of an overhang on your island to have barstools (12 to 18 inches)? Somehow they just don't look like they fit to me. Maybe it's an optical illusion, but doesn't look like there's adequate leg room.