I haven't red all the replies, so my apologies if I repeat what others have said. I like the black granite (primarily because it is less busy.) I'm sorry for making you question the backsplash: I feel that these narrow mosaics are (a) more contemporary and (b) quite trendy, so I'm not so sure they go with the raised fronts of your cabinets, nor are they "timeless." Because the counters and backsplash are pretty permanent, I personally would go with a more neutral choice.

I am also always drawn to this inspiration pic of jute/sisal look with light gray walls too, but my husband likes gray as he thinks it won’t show as much dirt and wear....

also, our new light fixtures will all be black and modern, if that helps. our mulch is black as well

It's your office; standing desk and w/multiple displays, it would seem you spend a decent amount of time there. Also good that it looks as tho you do not need a window covering: Good, don't put anything on the window to hide the view [or light]. If it were my space, I wouldn't give two hoots about painting a certain color because of the smallness of the room, nor necessarily care what the existing paint color is. I would paint this room that I use, the color(s) I like. Period. As others have suggested, do consider the ceiling as a paint-able surface, where color can be used. Screw always-white ceilings; I don't buy that premise. Boring, trite and predictable. Not saying white shouldn't be a choice, just that white shouldn't be an assumed choice. Since it IS a small room, and it IS your (private) office [versus guest room or living room], why not consider something crazy, like painting all four walls different colors? I know...outlandish. Or highlighting the window trim, since the outdoor scenery should be made a focal point. As leslie said, why not be facing the view as you work! I just think sometimes it's worth it to step outside of the normal boring box. Make it something un-boring and Fun.