This might be too dark but I liked it.

I like it. Just go light with the grout.

Glass subway tile (3" x 6") in a neutral color and grout. It looks beautiful and is easy to clean. Design-wise I think it is classy, simple but beautiful, and will always be in style. While I like mosaic glass tile like the other commenter posted, I really think it is much too busy in kitchens, especially when for practicality you have items on your countertops (knife block, canisters, spice rack, etc.). I think it won't always be in style either, it's very trendy in my opinion. I did a "Cashew" color glass subway tile with white grout to go with my dark brown quartz countertops (my wall color was an off-white lighter than your olive color) and it was BEAUTIFUL. I also found that its reflective properties were a plus and I didn't need under-cabinet lighting. It looks like your countertops have no backsplash at all so I think if you go with glass subway tile you will love it! I unfortunately had ugly oak cabinets (I'm attaching a picture of mine!) but it looks amazing with white cabinets also (I've found a sample pic on the internet I'm attaching also). Anyway, hope that helps! I bought my glass subway tile on Amazon, it was fairly inexpensive, I got free shipping (with Amazon prime) and got free return shipping on one box I had received with a few broken tiles.

Thank you...I really like this suggestion