Well, from the sounds of things, I would put a "stop the presses" halt to any backsplash shopping right now. You have so many competing colors among all the surfaces right now that you run a high risk of making a mistake if you choose your backsplash before everything else is in place. Let the renovation run its course, try to get your designer to take a raincheck on backsplash assistance, and then re-evaluate when you can bring in samples to the completed space to evaluate in your specific lighting. This would be the normal course of action and sequence for any backsplash choice, but in your case, I think it is imperative. What is throwing me is the apparent combination of warm wood tones with gray and black paint and also the gray and brown combination in some of your countertops coupled with what you are calling a "pure white." There is just so much latitude in all those colors to skew one way or another that I think your safest approach is to wait it out until you can see how things come together. You have warm and cool tones mixed and colors that normally wouldn't be put together. I can see this working out, but it is going to take some precision on your selections. Best wishes on your renovation, and please come back and re-post when you are ready. If the contractor is insistent to do the decisions early, please try to negotiate some time with him until you can compare all your color choices at once in the same lighting in which they'll be installed. The backsplash can make or break a kitchen design, so you want to get it right the first time. It cannot be pulled out and re-done without sheetrock and possibly other surface damage.

Get the design right first before you match plaid pants and a striped shirt. The whole design is based on such rigid symmetry that the fact that the hood isn’t centered on the room peak is incredibly obvious and throws everything off. You either need to introduce some deliberate asymmetry or go back to even more rigid symmetry.