Deep gray and all the other accents in silvery old wood and cream. This will add drama, allow the other elements to bring ion light and set off the concrete wall as a true feature. If you want light instead of drama, then go for a very pale beige stone. It will echo stone colours in both the concrete and rocks...

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.

The blue is awesome (grey is too trendy)! The reason it stands out to you is perhaps because it's the only real colour there. Bring in the blue in a window treatment, a small appliance that sits on the counter, a pretty tray or area rug. Also, it is more appealing often if there are more than 2 colours - so right now you have a white and blue colour scheme - bring in red or orange or fushia - something from the other side of the spectrum (like you did with the yellow flowers but in a more permanent way)!

Add colour . Please add colour haha . Just a thought though , instead of paint ( its a bit hard for me to visualise everything from your description -- I am a visual person ) how about maybe those translucent blue looking tiles ( yes , I know , extra cost ) , you may even 'frame' them in the white tiles to tie in with the shower , or possibly do the blue instead of the white , or even do the shower in them , and have the rest your 'white' walls . And when I say about those tiles , you can get them in square or subway or even long skinny ones , or even long and skinny but with long skinny darker blue and brushed ali ones too -- in other words , have fun and add interest !