Id use a patterned tile.. not just one primary color. Search your tile store and bring a few home. You have an abundance of the putty tone in your space.....get color in the plural / pattern would be my pick. pick up the theme w bar stools instead of painted ends.

heres a few..it would be nice to work w the bit of warmer mixed w the blues in the first two.....anyway....pretty up your space and put in some interest.. Stark blue tile is too much of more "cold".....employ blue, if you like it, WITH other colors. Colors are harmony and it will benefit your kitchen.

Tuscan Tile Peel & Stick Backsplash Tiles, Panel · More Info

6"x6" Mexican Talavera Handmade Tiles, Set of 40 · More Info

Aegean Peel and Stick Backsplash Tiles, Panel · More Info

GDF Studio Santino Blue Fabric Bar Stools, Set of 2 · More Info

lumisource Fabrizzi Adjustable Barstool in Walnut Wood, Blue · More Info

Tile Mural An Iznik pattern pottery tile Backsplash 4.25" Ceramic Matte · More Info

Never paint just half on an island. That's really weird.

Just do the tile and then bring the color over to the island with blue stools.

I think with the openness of your kitcen, painting a bold color will be a challenge on where to stop.

Would you consider a green? The putty color of your cabinets, to me, lends itself to a more earthy color.

And I'd do a backsplash, Kitchen Aid Mixer, barstools and a couple funky island pendants (looks like there is a prewire)

DO NOT paint the island.

I would not paint the island. Painting half will not look nice. Put in your backsplash, and then add the blue in stools and accessories.