Maybe a light silver colored grout? With regular sized tiles, there isn't usually a large grout line. If you go darker, it will look more like a solid surface. Is that what you want?

I'm not a designer but I just picked out the grout for my various tile work with the help of my designer.

My tiles are not the same as yours but they are also showpieces so to speak - i.e. not flat white subway tiles :-).

With the guidance of my designer I picked grout that closely matched the color of the tile so that the grout itself wasn't an additional design element. FWIW, I like the way your tiles look right now without obviously contrasting grout. They are obviously tiles but the tiles themselves are lovely enough to be the only necessary design element.

My vote is no contrast.

For some reason I couldn't comment before. Which of the looks I posted do you prefer?

Grout as close in color to the tile.

Pick a grout color in the same color as your tile. You could go a little lighter or darker, just stay in the same color family.

No white!

I think if you try to match the tile it will end up slightly lighter anyway and create a very subtle contrast.

Normally i'd say match the tile, but with the way this is laid out, I'd do a light grout color. (beautiful tile btw. what is it?) You want a subtle delineation or else it will look like a one solid wall of color.

if you match your grout exactly to the tile, you might as well as just painted the wall that tile color. you should be able to see a slight contrast.

do a very light gray like Mapei Warm Gray, or do a darker bone white color.

on the left are Mapei and the right is Custom

closest to the tile color is my vote. Also easier to keep clean than white

Someone has one called Silver Shadow, can't remember the brand. I used it in a bathroom with gray-blue tile. Its a little lighter than those. It might work for you

I agree 100% with Beth H. Just a slight delineation would make the tile stand out. You do not want the wall to look flat and like it is painted yet you do not want stark colored grout. My vote ever so slightly lighter.

suzyq, Silver Shadow looks like Laticrete's grout.

Vespa,,,are your tiles more blue/gray or brown gray? hard to tell from pic. the one above leans a bit warmer toned. if that's the case, then you don't want to use a blue/gray grout. If you will have that color lighting (a bit yellowish) then take that into consideration.

Who makes the tiles?

it may be a good idea to make up a sample board. lay out a few tiles on a board and grout them w/a cool blue gray, a lighter grout, and a grout the same color as tile. then see what you like best.

ok. that's what I though from your picture. so you need more of a warm gray. try some of the examples I posted w/your picture on my other comment.

Everything you're doing is gray except the cabs? You need a lighter grout in the same tone as the tile. Sometimes white with a touch of your gray really works to pull it all together with the cabs. If you go darker, you are going to pop the white cabs by making the "accent wall" look like a solid color. I'm not saying that's bad. It depends what you are trying to do. Are your tiles warm gray? Or pure gray? Can't tell.

Bone grout next to the oyster grey color of your tiles:

just for reference, here is oyster gray grout w/the white subway tiles.

smoke gray is nice. what if you did a lighter color that wasn't gray?

Its too hard to tell, on my screen that tile looks warm, like dark taupe and the light pewter grout looks like a lighter version of the same color.

I like your smoke gray beside the sample. Hope to see your finished wall. What are you using for your counters?

looks really nice. question...why the white outlet way up on the tile? can't imagine what you plug in up there. you could buy an outlet and cover in a gray color that would match your tile. that white one just really sticks out!

ah, ok. that explains it. I was trying to imagine what was going there and still allow the upper cabs to open.

where did you find that tile? it's really nice.

It turned out really nice. Good grout choice.

Vespa, really? lol. can't believe you carried that entire batch on the plane with you! what a great deal.

It look great! Just the right amout of contrast. Enjoy your beautiful new kitchen.