Im not sure how much brick is seen around the window frame, if its only a little brick, you could paint it, although I'd prefer it be a smooth rendered finishor plaster like your other finished walls, because if there are three surfaces visible in there, none will be a feature, and all will look incohessive. To let the ply wall take the focus the plaster is perfect in contrast, so if absolutely necessary, pair. He brick white, although my recommendation is to gy rock and paint, just with he back wall in marine ply. Good luck, I'd love to see your finished result. By the wY, mentioned split battens to hang the ply, if you're unfamiliar, it's where timber battens are cut in half on the diagonal through section, and one half is fixed to the wall, the other the ply sheet, when they go together they become a secure locking fixing. Any handy person or tradesman will know how to do hat, without glueing or messing up the brick wall. It's quick, cheap and secure, and best of all can be removed without much effort to allow you flexibility in time.

I had my house rendered last year. To decide on colour, I first drove around looking at rendered houses, to get a feel for the colours & tones I preferred. Then I used the "Paint Your House" program on the Dulux website. You can either look at their various "stock" houses, or upload a photo of your OWN house. Then, using their colour selector & painting program, you virtually "paint" your house, so you can see what it will look like when done. Once I'd narrowed it down to a couple of colours, I got sample pots in full-tint, half-tint, and quarter-tint. Painted sheets of papers with them, and stuck to outside house, so I could see what the wall colour would look like during various times of day / sun vs shade /etc. It was a bit stressful worrying how it would look when finished (since I went a deep ocher gold), but I'm thrilled with the result.

hahaha tribbletrouble...U kill me :)) No charge - every week they have a free consultant at my local dulux paint shop :) Question - Do you think Surfmist matches with Colorbond Dune ?

Go grey as advised above, don't paint window frames if they are metal but leave alone, plant sasanqua camelias along the side boundaries (they can be hedged) to screen out neighbours & add greenery plus colour, landscape the front. Don't do white stones as they look dirty after a while and are blinding in the sun. I'd get rid of the stones altogether. If you are a gardener, put in box hedging and some standard roses (yes, I know done to death but they are charming), or draw up something on paper first - play with shapes. A garden makes a house look good.