Ok so depending on floor colours and overall look that she is going for I think (if she is really adamant) that the blue could work if you change the Amaro cabinets to a whiter shade - this will give it an overall crisp, oceanside feel with the warmth of the soft walnut. Otherwise I would contrast it more with a mid-tone colour splashback in grey/brown tones. Again this totally depends of her tastes... Here's a photo that you could show her with the blue splashback - granted it is a little deeper than her selection but at least she can see it on a realistic scale and of course the timber/white cabinets are flipped in this one. Hope some of that helps!

We have tiles that do not have a gloss finish. They are Encaustic, or at least I think that is what the style is called.

The tiles from Johnson in the UK are stunning. It appears they only come in large 30x30 ? I was thinking of doing some sort of tile art just in the middle of the backsplash with the rest just plain offwhite tile. However, with this large 30x30 art work, the background tile would have to be cut to size to fit the area I have and might look too choppy???

Thanks Kate, mine is more a kitchenette in a 1930's garage conversion - chrome tapware, red bricks, black cabinets and bamboo benchtop, high ceilings with exposed beams. It has a similar vibe to my fantasy kitchen but on a micro scale. The bricks are beautiful, with some kind of varnish on them already but they are super irregelur and bumpy. I love the idea of a hinged lid over the stove top, which wouldn't detract from the seamlessness of the bricks as I feel a glass panel would. Glass gives off that blueish tinge and would interrupt the flow.