I hate to say it, but those two stools don't play nicely together. These look more like you bought some stools, and then you bought some more in a similar color. Like you couldn't find the first ones again, so you settled. A little more contrast between the two would be better. With some element that is repeated in both stools, but not necessarily in the same way. Edited to add: Here is an example of what I mean (just two pictures I found on Wayfair, not suggesting them for anything): Stool 1 Stool 2 See how the stools are the same color, even though they are different shapes. The color would tie them together. Here are two more: Stool 3 Stool 4 See how the wood and white (assuming that's a white and not a cream!) are flipped? The chair version would really go well with Stool 3 -- not so sure about the stool version of this one..... Anyway, these are just for illustration any....

Consider width as it’s important given the small space and no arms to make it easier to get on/off (and less need to be moving chair as often on your wood flooring). A back is more comfy if people will be sitting for any length of time and safer for younger children. In regards to color/style, I could see a wood and black combination. Although not light, I think it’s important to tie in well with your kitchen‘s style and flooring and also connect with hallway’s flooring, for a smooth visual transition. Well priced and see reviews. https://www.target.com/p/ceylon-woven-counter-height-barstool-black-black-opalhouse-8482/-/A-82267500?epik=dj0yJnU9YVpCZ2JWMHY2dlBYajR6eHhIeW9XcWdHQkxiOFFDd1kmcD0wJm49aWx4OG9ZWnRqdlZpQ24xN3VJOVg2ZyZ0PUFBQUFBR1FQT29j&preselect=82057808

Thank you both for the suggestions! I'll check these out and run them by the spouse who has thoughts. (I also kinda like the one you got for yourself, Chicagoans--that would probably look good in my kitchen! There is a reason I've been without stools for so long. I am all over the place.) I'm looking for something that won't fight with my old kitchen set which is at the other end of the room. Maybe that's why I keep looking at boxy stools instead of curvy ones? It looks like this one below but with plain green seats. I don't need it to match but I'd like it to agree. The stools would be at a walnut island so I want something either contrasting or...walnut? I think. Maybe. Probably not oak.

You could try looking for stools with substantial enough feet to attach sliders to. Perhaps not the most elegant solution, but it would be practical. Good luck!