I think white against the dark grey has the biggest visual impact but with dark grey windows. If you wanted something different you could always try a different colour over the door area or even the oak. I can't unfortunately find any images..

Hi Adrian, Looks like a lovely project. Personally I think an Anthracite grey aluminium frames would look very sleek and modern with your design. Here are some examples we have installed for our clients; hope this helps... we are also on instagram @croydonwindows which shows a lot of are work unto date. This one above is a new build to be completed next year which we are quote for our client we work with on a regular basis.

Hi, We are planning on installing 2 new windows in the living room either side of the fireplace and 2 new windows in the dining room on the same wall (you can walk from living room through glass doors to dining room so you'd be able to see all 4 new windows along that wall as soon as you walk in the living room). We want to put sash windows in there but wondered if this would go with our current large living room window (please see photos - excuse the mess!)? I like the simple 4 pane ones and my husband likes the 12 pane ones. The wall they would be going on is west facing so we'd get lots of light (800x1200 living room windows and 800x1526 dining room windows - planning already passed) and that wall is on the side of the house that has no windows currently so wondering if we could get away with it! Our builder suggested it might look too busy for the 12 pane ones. Living room wall is 4.5m (room 5x4.5m) Anyway, please let me know what you think (current living room upvc window will be painted white to match new windows). Thanks for any help (I've been trailing pinterest for literally hours trying to find a way to work out if they would go!).

Yes it’s Pigeon. As you probably know, paint colours can be greatly affected by the light in a room. It can look quite pale in a south facing room, but in a north facing room it can look pretty dark, almost dingy. Try the paint on some card and move it around the room, you will see it change. Here’s a couple more Pigeon pics and you can see how different it can look.