You can get any colour paint you like in any strength - 1/4, 1/2, 3/4 or full - its only a colour, so they will mix it to your request. Have you made yourselves a colour board? if not, you will need to get all your selection colours together and then go to bunnings or a paint shop and get some sample pots of the colours you are debating. (yes it will cost to get sample pots, but seriously you need to do it - and get the varying strengths in the same colour as well). If you are worried about the render colour marking, go the 1/2 strength on the render and 1/4 on the mouldings. Your Wow factor will come with your varying textures - brickwork/render and trims/timber doors, and the wrought iron. I'm guessing you have exterior lighting? some beautiful exterior lights will be the icing on the cake.

What about one of these for roof and deck railings? Trial any colour using sample pots before you commit to purchase, as how the colour look can certainly vary. If if you are hiring a painter for the roof, the downspouts could be done at same time. I would not attempt to paint the spouting myself for reason you mentioned. Otherwise, leave them as is - as lush as your garden is, they may not be noticeable. As for your decking, is it painted? If so, I’m pretty sure you cannot oil it, so could either leave it to weather or repaint it.

I don't think it will look bad when landscaped, perhaps with a raised bed in front of the window. It would be nice to introduce another hard finish but I think maybe timber....one of the photos has a large timber step/ platform which might work here. Whar sort of fence are you planning?

Agree on the cedar , and I'm not sure what condition the roof is , but if you do need to paint , keep it similar and light . The areas I would focus on are the door and the gutter . The brown gutter does nothing to help , but keeping in the 'organic' spectrum , I'd go a mid to military green for the gutter . The door and the window frames around it I'd go a mid yellow -- say a mild buttercup or similar , so it stands out but still looks organic . The small deck and wires I'd demolish , go wider so it stretches from below 1 window across the door to the other side , so around 3 metres long , but with uprights and a pergola style roof -- all done in monument or similar OR if you can source the sizes , maybe cedar . Possibly have a bench seat one or both sides , even marine plywood cupboards under them . They are still liable to get wet , but use for garden tools , hoses , spray items , or sitting on or decoration -- sort of get that rustic thing going . It just needs a boost around there , but anything too shiny or modern or tacky will distract .