I think if you found a subtle mosaic tile to do the backsplash with blues/greys/white it would tie it in together fine. Honestly I get the feeling that when in the kitchen it would seem quite nice (as far as blue kitchens go). What jumps out at me is the back of the cabinet that is facing the carpet. I think if you could cover that with something neutral the kitchen would blend in better with the rest of the room. You could get a cheap vinyl cover/end panel to put over it (even one that matches the Benchtop would be better), or tiles, or wood panels/slats - so many options :) Can I suggest you take a photo looking straight into the kitchen & then re-assess what bothers you from just that perspective?

sounds like lots of colour going on. What colour are your window treatments? what about timber chairs which pick up the flooring & colour in your bench top (stained IKEA style or bentwood) & then some grey accessories... its about your eye matching the same colour for uniformity. does that assist.

http://www.potterybarn.com.au/hayes-tufted-upholstered-barstool Not sure if these are leather though, sorry.

would any of these do? https://www.huset.com.au/home-furniture/dining/bar-stools