White with black trim
http://houzz.com/photos/186190

Can barely see it, but this gray with black is good looking
http://houzz.com/photos/140440

I think I am really liking this natural grey linen look. As it gets quite cold here in the winter I could run a two rail curtain rod and combine a thermal backing and then the grey linen. I did really love the black and white stripe but think it might over power what is a small space. I might consider them in our extension though! Thanks heaps for your input!

bellene1169,
A nice charcoal perhaps to give the room some mood and glamour

White curtains or very pale grey will keep the light levels high in your room and make a nice backdrop to your furnishings. I think patterned curtains are more casual and with the amount of windows you have, they would make a huge statement in the room. Darker curtains will reduce the light and can make the room look dingy. If you felt you don't want perfectly plain fabric, look for a slub fabric or something with some interest or texture in the weave. You could even have a self stripe which can look very elegant.

I have just finished new curtains through my house and did the double track where I could and used a thermal lining that I can pull across to keep the cold out and it worked very well and is also working well now in the heat keeping the rooms cooler - in fact it is amazing some days the amount of heat trapped between the curtains and the windows and kept out of the room. In my bedroom I used a heavy sheer curtain to be able to enjoy the view of the garden while still maintaining privacy and the thermal lining gives me full privacy at night. I'm thinking this could be nice for your room when you have such a lovely outlook too and you do need something to keep the sun off your furniture and furnishings.

There are also thermal roller blinds you could use instead of curtain linings, these do darken the room but they work very well. If you use the linings though, there are different weights, I used one pass in my bedroom and other rooms, and it does not darken the room very much at all. In my lounge room where I really needed heat blockout in summer, it was a bit of trial and error - I used triple pass and it does significantly darken the room to the point of totally gloomy - I really don't think I would use it again.

White sheer curtains or blinds for privacy still gives the most beautiful light and allows you to see your wonderful outlook. Have pale blue heavy plain curtains that are mainly left open with a couple of matching pillows on the corner cane chair. This will keep the room spacious and still neutral and blend well with your outlook and your grey, black and white colour scheme. I think having the grey linen curtains will close the sense of space in and prevent you from connecting with sun in winter. Best wishes.

Hi to all who gave their thoughts and input into my post. We decided to go with a light grey linen which was a compromise between the duck egg blue I had wanted and the black my husband had wanted. It has made massive difference to the insulation of the house and we still get to enjoy our views. This photo was taken in the middle of winter in the afternoon so we are still afforded plenty of light. Thanks again to all who contributed.

Thank you for the update bellenell, it is always nice to see the end result. That is the exact weight of curtain I had in mind. Looks good.