A green roof pairs well with gray and white homes. For a subtler look, pair a green roof with a siding in a lighter shade of green. I think you are on the right track .You have chosen harmonious shades . New paint doesn't have to match existing colors, but it should harmonize. Some general tips are- Green roof - Gray, green, or white house colors. You could use a dash of yellow also.

Blue gray window frames match the funky roof. The cedar is diametrically opposite on the color wheel as a orange tone. Usually the browner grays (sort of the light shade now on the stucco) do better with cedar to say modern, but since you have the blue gray, allow me to suggest that you just go as dark gray as you can - nearly charcoal on all the weatherboard. If you are in a high heat area (palms might or might not be - that might be the ocean on the horizon which might me an onshore breeze all the time) then you want a white. Not a blue-white but a warm white - bm maritime white is a good choice. With the cedar and the two blue-blue-gray elements, you need neutral without tone.

This just popped up , but I see it is quite old . Did you decide on paint colours ? The roof looks almost a brown tone in the photos , but you say it is dark grey . I assume you don't want to paint that ? If you do , go more charcoal IMO . If you don't , I'm assumimg it will look several shades darker with your wall colour choices . There is a roller door on the garage that appears to be a nice shade of orangey yellow . Personally , I would go with your colour choices , but do all the doors ( roller doors , wooden doors ) and gutterings in that ochre shade . Your terrace I would do in a charcoal , but with the top rail either in the orangey yellow , or a really crisp white . I know that sounds a bit 70's ( although they would have added a lot of ranch brown back then haha ! ) but against the light grey I suspect it would work together well , and look the part .

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!