Agree with carrieandjimh, You will need to connect the two colors through prints on pillows, curtains, rug etc. Can you post a pic of the sofa and wall color so we can see what we're talking about here? Thx.

Wish i found this Q &A before. So many beautiful people advising and sharing here! I am Repainting Tropical Queenslander with dark red and orangy timber floors and this thread is so helpful. I painted Whisper white and it is throwing so much Green it makes me so sad I am going to repaint. I get loads of tropical sun in the north facing - with eastern morning sunlight. Was just about to go and buy Natural White just to cover it. Do you think it will be too dull/warm a colour. I do like a fresh feel and contrasting with vivid white decorative trims. The whisper white looks nice For a while in the morning while the morning sunlight throws read up onto it but then it returns to a green

You may use a specific light in the grey on the wall were there are two windows. While the other wall with a long slim window has a wall feature design. There are numerous features to use, with the intension that it would be on the same colour contrast. As was mentioned that the blinds would be great sprayed though in a colour that will go with the walls colour and design. Need to be a balance in the colours for both walls and the blinds. You may use one wall with wallpaper feature if you prefer. I have found a site that may assist you with the design of your choice. http://colorhunter.com/; http://www.resene.com.au/wallpaper/#

As a former art restorer and now retired I am proficient at mixing colours, I agree with the two above me taking the pillow case is a good idea and the other thing is to do is make sure that the grey has a blue touch as some have a green touch or a brown touch etc so it is possible to get the wrong mauve grey which has a red/brown base to the black and white to achieve the mauve/grey, overall the paint store have people who will help you pick the right colour as often a colour on a small sample looks a lot different when applied to a whole wall. Good luck