I think that more contrast might be the answer. Your table is dark and walls gray which absorbs light. Floors medium to dark. I think the shape of your first chair works but it just recedes into the table because it is dark in color. I chose these mainly for the lighter color and keeping with the MCM shape. This one has a transitional shape but I think the zebra print would give you some interest Also have you considered an area rug?

Why are painting the legs black???????????

Correctly made Windsor chairs are the strongest wood chairs ever made and will take whatever the family can dish out, and go with your decor. There are a lot of poorly made ones, its important to get through-the-seat and bows, bore and wedge construction. Good ones will be around $ 300 to $ 400 apiace. https://www.lawrencecrouse.com/side-chairs/ I have a set of (4) Black Sides in my warehouse if you are in the locat Washington DC region.

Even PB table and chairs will not match exactly because they are not made of the same wood. Maybe you want to consider contrasting the chairs with the table. Chairs are often made of rubberwood, maple or poplar. and not oak or fir.