Brittanicca will work for transitional but if you want 'warm' then maybe go with Brittanicca Warm instead.

Brittanicca Gold would be great, with the island cabinet color on the left.

Here's a picture for you

Some backsplash options for you

Modket White Glass Matte Herringbone Mosaic Tile Kitchen Backsplash TDH69MO · More Info

Metro 3"x12" Glass Subway Tile,Glossy Arctic Blue, Set of 40 · More Info

Frosted 3"x6" Beveled Glass Subway Tile,Matte Blue, Box of 112 Pieces · More Info

We put Portrush in our powder room in a coastal home. It’s beautiful but definitely a good amount of blue!

Hello Michelle,

Cambria Brittanica looks great with white cabinets. I think it will look good with your flooring choice as well. We used Cambria Brittancia in this home remodel. Here is how it looks with white cabinets. https://www.houzz.com/hznb/photos/modern-townhouse-modern-kitchen-seattle-phvw-vp~164866491

https://www.houzz.com/hznb/photos/modern-townhouse-modern-kitchen-seattle-phvw-vp~164870569

With the portrush

Subway Glass Tile/03, 3" x6" Tile, Set of 40 Tiles · More Info

4"x12" Baker Glass Subway Tiles, Set of 3, Turquoise · More Info

Modket Gray Metallic Wave Glass Stack Mosaic Tile Kitchen Backsplash TDH232MO · More Info

Wister Beveled 5.1"x6" Glass Mosaic Tile, Slate · More Info