I think white walls would make the jarrah a feature, maybe antique white

So excited to here about your theme! We are currently extending our house with a similar theme and colour style. We have gone with 'Solver Parchment' in our kitchen (and most of the new section actually), it is not a yellow or cream colour, more of a beige undertone. Lots of warmth and not too strong. Quite similar to half strength Dulux Hog Bristle. (We don't have kitchen cabinets just yet). In the master bedroom we have gone with 'Taubmans Morning Fog ' which is a lovely duck eggy blue colour, very calming. Could also work with your blue accents. Both match with my Laura Ashley wallpaper feature walls very nicely (Laura Ashley Josette in Duck Egg and Sable). Ceiling, cornice, archs and skirts etc all in 'Wattyl Magic White'. Nice and fresh. See pics - please excuse the samples messiness, they have been rolling around in my glove box for a while. Look forward to hearing what you go with and seeing a pic.

Hi Brett about 5 to 10 years ago the trend was if your design style was contemporary your trim colour was the same as the walls and if your design style was classic your trim was a lighter, often white contrast to the wall colour. These days the trend is to the latter regardless of your design style as your builder's designers suggested. However matching your trim colour to the walls is still a good option if you have 8' ceilings. As there is minimal difference (only in the level of sheen) between the skirting boards and wall colour it makes the ceiling look higher. Another option is to do the trim in a similar but lighter tone such as Dulux Grey Pebble quarter. This is a very subtle tone on tone look. Whatever the colour, do you have a choice in the sheen level for your trim? I generally recommend semi gloss enamel on trim unless you are after a more classic look and your woodwork is in very good condition (the higher the sheen level the more any imperfections show up), in which case you could consider full gloss enamel. At the end of the day it's your home so you should do what you'd prefer - after all it's only paint so it's easily changed! All the best with your build.

there are some interesting putty grey colours in the knots of your floorboards. I reckon it would be worth holding some paint swatches up to the boards and see if you can find one that ties in with those driftwood tones in the timber . Then order a sample pot in a half or quarter strength version of the matching colour then see how it looks. Otherwise it is so hard to go with colours people have named, as every space has different light. If you are happy with the colour of the floor boards, let them guide your choice and you can't fail (as long as not too dark). :)