This where the OCD me would get out a large sheets of paper and start drawing many to-scale diagrams of the tiles to try on the wall to make sure I get it exactly right.

I would also consider whether any layout will be interrupted by outlets.

Thanks! It looks like I will be able to fit 2 complete tiles (alternating with one plus two half tiles) between the borders and have it adequately visible. Outlets would also be inside that area.

Does it matter what goes into the few inches above the border? It will be visible from the kitchen table and possibly across the room. I could use a trim piece with a bullnose for the border there and just fix the paint above it, or continue diagonal 4x4 chunks, or just do straight 4x4s above.

I just realized I'm trying to make my backsplash look like my bathroom floor. Teehee!

Could you do a picture? If you are doing matching grout for the diagonals within the border I think I would do a straight course above to fill in.

Thanks. I won't use a contrasting grout although it won't match. We're probably going with a light green tile and will try to minimize contrast. Grout lines will probably not be tight.

Here are some appropriately sizes tiles taped up. (The fluorescent light will be replaced and moved toward the front of the cabinet.)