May I suggest a cap of your pavers on the wall and the a slightly darker gray that relates to the privacy fence beyond? That way horizontal surfaces and vertical surfaces show similarities and blends/blurs the separations?

As the appearance of the garden has a modernist style with the straight lines and concrete furniture how about a Mondrian influence and add a bold strip of blue? It is a pond and with the right shade it could look really relaxed and contemporary. My daughter's suggestion is a chalky lilac!

Bronan, if you are over 13 and under 21, then the possibilities are really fun with black wood furniture in a room that could be set up with a ballet barre, or used as a dance practice studio as well as a bedroom! Since the floors are dark, you will need to keep the walls light, Usually in a bedroom you start with the colors in your bedding. If you want a new look, perhaps you could start with a pretty floral like this, paint the wall where you will put the head of your bed a deep coral pink to match the bedding and all the other walls a pale pretty coral too. room a soft, soft pink, and hang soft pink drapery panels http://www.target.com/p/threshold-multi-floral-comforter-set/-/A-14982101#prodSlot=medium_1_13 The coral will pop with your black furniture better / a good one that makes your skin pretty in the light - this one for a headboard wall to test - http://www.sherwin-williams.com/homeowners/color/find-and-explore-colors/paint-colors-by-family/SW6878-animated-coral/ this one for the other 3 walls . . a white with the same coral undertone - http://www.sherwin-williams.com/homeowners/color/find-and-explore-colors/paint-colors-by-family/SW6609-touching-white/ If possible, you might hang drapery rods on the mirror wall, so you can hang (with this bedding) white drapery at both the window and on each end of the mirror - it will make it feel a lot softer in the room if you treat it like a window. You can follow watch for on sale drapery until you can get a lot that is the same. Put the rod at the same height over the mirror as it is over the window. You might paint an inspirational quote at the top of the mirror in the dark coral (using a stencil) so that you visually fill the space between the top of the mirror and the top of the window. You could get a sample size of pale green paint the color of the green in the bedding to paint an extra piece of furniture that you need that isn't quite right. A little desk or vanity, or even a round end table or a bench for the foot of your bed. Hope this looks like an interesting option to you. Later, you can go for graphic black and white bedding and put hot coral pillows on it with the same paint job and curtains and get a whole new look with just new bedding.

Thank you everyone for your ideas. We are about to paint the walls an off white - double merino, and thought we might paint the doors and pelmets the same and now after reading your comments I think we will leave the timber beams and paint the ceiling between them the same as the walls, and will consider the bar supports too. What do people think about painting ceilings, doors and walls the same colour?