That's a tough one. I want gray, but when my eye gets to the floor, I fear that gray won't look as good. I say go with a neutral buttermilk color that doesn't have too much yellow in it. Some other Houzzers might have some specific color name suggestions.

For now, I'm thinking in the lines of:

http://www.benjaminmoore.com/en-us/paint-color/lancasterwhitewash

http://www.benjaminmoore.com/en-us/paint-color/icicle

I like the lancaster whitewash!

How about this color? Or:

Ben Moore spanish olive. if too light, you can darken it by 25% increments. I have it and love it.

I'd stick with something close to your window frame white for the ceiling and a pale sage or olive green would be nice on the walls if that brings out the green in your countertops.
Consider bringing a wood valance across between the top of the cabs over the window - There isnt much wall left in this view of the kitchen, except on the two sides, so whatever color walls you choose - add a fabric jabot style valance with rod hung on the back side of the wood valance that stands away from/covers around the window and/or add window trim, as the tiny bits of wall that are left may actually look odd with color showing at all in that spot. Look for the fabric valance to help pull all your colors together - a moderate scale pattern with the wall color, your pale tile gray and some of floor's yellow. If you can bring in those same colors in place mats, napkins, small decor items, etc. it will also help it all work together

I encourage you to consider Para's Georgian Green Tint 2 - I have paired it with wood floors the same tones as your cabinets - it is rich in all lights and combines with most other colours - and I have to say that Para is fabulous to work with :) agree with bprince 300 suggestions for window treatment although I would tend to stay away from pattern as there is alot of stuff going on - I would tend to go for a solid, maybe daring hue - take a chance :)

pick the grey in your back splash tile for the ceiling color and the beige in your back splash tile for the wall paint.

SW 6149 Relaxed Khaki and SW6150 Universal Khaki-----if you prefer a little more color check: SW 6171 Chatroom and SW6172 Hardware. One of those will work for you. Very nice kitchen... CheerS! :)

I am not sure if you are even interested in green but Florentine Plaster by Benjamin Moore is a green/gray colour. Depending on the light it reads differently. The green makes it a warm colour which will look good with the cabinets and floor...Good Luck!

Pull out the green. Hard to tell from your pix, but get into the BM Affinity colors...flora AF-470 or azores AF-495

I love the backsplash!

I would definately pull one if the richer colors from the countertop- the ctop is getting a little lost right now
check out behr's desert moss

Might want to look at BM Shakespeare Tan

Can't see the colors in counter. Can you post a close up? I like Benjamin Moore's Quiet Moments but not sure if it will work with the colors.

I would pick up the slightly beige tones of the accent tile and the countertop for the walls.

I would go with a color that adds interest. Go with warm greens (olive) Right now everything is a generic beige tone.

HI ---Beautiful cabinets and I love the colors . You have had lots of colors mentioned and they all seem to be in the greens . I think you should pick something that will blend with the backsplash , one of the lighter tones . BUT ... I have spotted a possible small problem . I think you need to have a piece of the cabinet crown molding continued over the window area. Right now the way the molding ends is going to make it hard to fit a window covering . If you have the molding across the top then you will be able to have a roman shade hung from just at the botton of the molding and the full width of the window area . Then it will be a more tailered look. Another color idea is a soft pumpkin. If you get some color sample cards from Ben Moore ,that will help you .

Love Dytecture's photo---it's very close to the SW 6172 Hardware color I suggested. It picks up all your colors in your counter, backsplash, cabs, and floor...

Also love Dytecture's photo. Looks very close to my kitchen which is SW Quiver. Same strip as the universal and relaxed Khaki. Love it!

Perhaps Dytecture could do one with lancaster whitewash....the green is nice too though

love the backsplash what is the name of it. I have a similar kitchen color combo and and looking for a backsplash