It's a dilemma because you know your stuck with it for years once it's on. We recently painted our cedar exterior. Started by agreeing on a general colour and then buying a series of sample pots. We finally decided on dulux colour bond dune. Amazing in itself as we rarely agree haa. It was a nice mix between beige and grey. We bought the 10 litre tin and went to work. After completing one wall I thought the paint was taking a while to dry as it wasn't getting as dark as the sample. My husband thought it was because of the lighting. I took a piece of wood and painted the sample which we loved and the paint from the 10 litre can together and yes they were a different shade. The hardware store had accidentally mixed the sample pot in double strength. It was all fixed up and we really love the result. So it was Dulux Colourbond Dune. I think it would be perfect with your roof colour.

Thanks for the photo's it really show's what should be painted with what, just by looking at the first photo looking towards the stairs, the painted bulk head would really bring the ceiling down and then again the second with the bulk head above the external door, wall colour is the right choice for me. cheers

Suggestions from neutral colours: https://www.dulux.com.au/colour/colour-trends/2018/essential Ceiling & walls the same colour is a good choice for square set. There will be subtle hue difference in various lighting situations anyway, which provides depth and makes for an interesting look.

some photos would explain the dilemma