I think I’d introduce some wooden stools to warm things up and add some texture. Stools with backs are more comfortable than those without. IMO

Context is key. What other colors are in the kitchen, house style, flooring type, appliance type and finish. All that being said wait until the tops are installed if at all possible.

"A standard American roll of wallpaper gives you about 35 square feetof coverage, but waste and pattern matching usually takes this down to about 27 usable square feet per roll." I usually get a little more than 3 full lengths/strips for a full wall from a single roll. But wallpaper is almost always sold in double rolls so would give you double this amount. If you're watching your budget, paint is usually more economical. And better if this is near a sink or steamy cooking area. But, that said, if you're only doing under the cabinets down to the countertop, that's usually about 18" up and down. So approximately 15 strips of 18" paper per roll if there isn't a big pattern matching issue to consider. Most papers are somewhere between 24 and 35" wide roughly speaking so figure out how wide your paper actually is and you'll have an idea of the coverage you'll have. For "most" kitchen backsplashes, a double roll should be enough. Good luck! Hope this helps.

So what you're saying is that you don't want a plain boring white rectangle offset tile, which is wise since everything else in your room is white. There are SO many choices in many different shapes, textures and colors. You can be creative with pattern--stacked, offset, herringbone. You can do square offset, arabesque, fishtail, in a dizzying array of colors and textures. Texture is a great way to add interest, I like glossy glazed brick, zelig or crackle tile. Try to find hand-made tiles which are much more interesting than the mass-produced ones in the big box stores. Go to a good tile showroom and bring home samples--these stores usually have talented designers on staff who can help you select something you love! And definitely do not rush. You can cook in a kitchen with no backsplash for as long as it takes for you to find your preferred tile. Here are some of my favorites: Zelig tile: Gray-green mottled color: Close up of zelig tile dark navy or black fishtail: Green glossy with accent on top: Another green with varying color: Square and rectangular white tile in an interesting pattern: Bright green glossy: Gray rectangle with smaller rectangles in niche: Gray rectangles with black liner: Large turquoise arabesque: gray crackle with black and beaded liner: