I would choose an soft white/off-white color that you find in the granite, solid color, simple rectangular shape. You need the splash as quiet as possible here.

Simple soft warm white and use the same color grout as tile so as to minimize the pattern of the grout lines, which would otherwise introduce a new pattern if you use a darker color grout against light tile.

agree with @apple_pie_order a simple tile in the creamy of the granite. Compare it to your floor tile too, so you get the same soft shade.

Not Yellow or Gold tone or you will only make the room glow with the cabinet color.

I'd choose a simple tile, same grout color as the tile color, not contrast to calm down the space.

I'd change out the hardware on the cabinets too, brushed nickel. I'd paint the island base, a simple change from all the wood in the space.

^Agree with all suggestions…simple and quiet.

Thank you all for the feedback- that is what I was thinking too…simple, light and muted. I just needed reassurance

Look for tiles called cream.

I have never seen a backsplash like that.

I was just scrolling by and that picture caught my eye. I had to enlarge it to see what I was looking at. How, uhh, imaginative. I wonder what that cost.

Yes, plain and simple is what you need.