Everything depends on your existing countertops, and the white of your cabinets. Pictures will be needed.

This is my kitchen so far

Are you having the island custom made and painted?

What is the lighting in the kitchen? I see a yellow, can you change the bulbs to 4000K? For a natural white. Then you can paint some large swatches on Sheetrock or poster paper large enough for you to see the color, in the morning, afternoon, and night. Live with them a while and that will let you know which way to go. Some greys look green, purple, etc.

Of course come back and show us your samples.

The backsplash I think you can do better. It looks a little common and more cookie cutter than something unique.

Once we deal with the island and the lighting you can select a few samples of backsplash you like with an interesting pattern, color, design and we can continue to help.