I don't know how hot it gets in Auckland in summer (I've only ever been to NZ in winter!) but if it gets hot, then go for a pale colour. Dark roofs should be kept for cold places!

We just stained our section fences with Wattle Ebony from Mitre 10. Was looking for a charcoal color too, not much flexibility in color options with stains from the shelves at store. We sprayed on, rather than brushing. Is cost a concern? One of our to be neighbours was doing there fences at the same time with paint, he said he used nearly 100L of paint for 2 coats, we used nearly 50L in 2 costs - had similar amount of fences. I've included photo of it after the 2 coats

Something like this would be great!

Hey there. Go for a cooler colour palette and draw the eye to a focal point at the end of the hallway, a console table, artwork, a mirror etc. A cooler paint colour helps the small space visually recede. In terms of the doors, going slighter darker will again make the space feel bigger. Go half a shade lighter on the low ceiling than the walls, using the same colour, rather than bright white, which will look dirty in the low light. Good luck!