If you plan to usually leave the door open to the powder room, I would have the woodwork match. If you don't, then do what makes you happy on the cabinets. As far as colors, I like ice blue in the bedroom and ecru in the powder room. That's what I've had for the last 5 years since we had to rebuild (after a fire) and I still love the colors. (Remember not to use yellow or green in the room where you will apply your make-up.)

A white interior is classic and envokes a s ense of spaciousness, freshness and luxury. However, using all white wihtout knowing what makes white interiors work is tricky starting from scratch. The insiders tip is to build upon many shades of it with as much neutral based whites as possible. Use warmer shades on larger areas such as walls, and then layer with tactile surfaces in the form of fabrics, rugs, and upholstery. Tones and textures in this natural colour scale will unify it and help the key accent items come to life amongst a white space. Mostly, when we refer to a 'white' interior, it's actually referring to how it feels as opposed to the colour- or lack of one. Think of a a grey scale, starting from white, and shades of grey right up to black, this is what you need to do, replacing the black at the top of the grey scale with your version of a natural white, taupe, beige, griege or whatever your chosen warmest shade of white is. For some it's right up there at caramel, yours migt be a stone colour, then work backwards incorporating these shades and tones of white using key pieces to Soften or invigorate the space. As you build upon this, it will start coming together, and in fact, the more you do, the better it will become. Picture for example, a Sisal rug which is a natural rope colour, then a linen sofa in a warm white calico, with a cashmere cream throw and rich, ivory blended cushions, in velvet or tactile fabrics. Use glass, reflective elements or metallic furniture where fabric is not possible, like reflective mirror to reinforce the sense of light that white evokes, coppers, burnished bronzes or even polished metals in coffee tables, lamp bases and accent pieces. Lighting will make a huge contribution to this layering, casting (warm)beige shadows over your white room by evening. this is called 'ambience'. Start collecting your white swatches, and lay them out collecting tones you like along with fabrics etc. It will come together, just select your key pieces (expensses) like sofas and rugs first in your fave shade of white, then be bold with pillows, scatter,s lampshades and the rest. Have fun!

I don’t know whether you have done your painting or not but with your dark furniture and existing windows I would paint walls light warm grey and 150% strength same grey colour on the architrave .something different and grey , yellow and brown look good together.

Dulux whisper white. Get a sample pot, paint a large piece of cardboard and see for yourself.