White to match the shutters.

The fact you have asked 'what colour to paint exterior walls' , I'm assuming you don't want to do the roof , and personally I like the terracota , so I wouldn't either . But the slight problem looks to be you ( or someone ) has done the garden edges and that fence ( I assume a front fence ? ) in the same as the walls .

To do all that in white may be too white IMO , so I'd lighten it with an off-white ( surfmist is a good go-to ) but do the gutters and all the ridges in a charcoal ( again , monument or similar ) , then probably that front fence caps , and possibly that side fence ( it looks like coloursteel panels at present ? ) , all in that charcoal . To understand why I said possibly in relation to that side fence , see below .

To finish , I'd do the columns and probably the garden edges in a lighter charcoal grey -- think halfway between monument and surfmist . And that side fence ? Probably do the main body ( the uprights ) in the lighter charcoal , and the base in the darker ?

Typically white, bit a light grey with white features can look great I assume fence is clourbond which would be a shame to paint so look

Great house, I think white would look beautiful with the terracotta, you could always add a dark trim for contrast, updating your planting would really compliment the house, you could think an olive tree in a gorgeous Mediterranean planter, also add aged planters to give a fabulous new look.

White with dark trim. Julie Herbert photos are perfect. Paint dark trim on all gutters, fascia and especially the down pipes. Again: note down pipes in Julie Herbert photos. I would keep the columns and planter in white. To me that looks like an ordinary cement sheet Hardie Fence, on the boundary. Not Colorbond/steel. So I would paint the fence the dark trim to hide it.

Or if you don’t like the orange roof, this home a similar façade as yours, built 2002. They have gone dark roof and trim with a taupe render.