You can get Woodland Grey in deck stain and deck paint. In some brands it’s not called Woodland Grey due that being a Colorbond colour but they’re that colour.

Personally , I think it is too dark and too same same . I know you only asked about the deck ( and presumably steps ) , so maybe a light grey there , BUT I'd do all the trim in a crisp white -- the railings , the uprights , maybe the gutters -- although I'd prefer the gutters in orange -- maybe thats just me , but it needs differentiation and a splash of colour IMO .

Noo! Pottsy, it’s gorgeous, I love dark houses , maybe add planters for definition.

This is a black house . Personally , I wouldn't have it , although the garden is nice --

This is a black house with white trim . Personally , I would have it .--

This is another black house . Personally , I wouldn't have it --

And this is a black house with quite a bit of white , and I would have it --

But of all of them , my colour preference would have to be --

Each to their own .

I was thinking of painting the steps and deck colourbond evening haze which has a slight green hue or perhaps go with boring brown?????. I agree the window trims should be white

I'd keep away from any brown or fawn or chocolate or coffee .

But here is evening haze --

Here is Evening Haze with Monument ( I realise yours would be Monument with Evening Haze , but this gives you an idea ) --

Here is Evening Haze with White -- getting a bit better IMO .

And here is Surfmist . It would be my pick for the terrace . You'll also see this has white trim .

And , you guessed it , here is Monument , Surfmist and White --

If you wanted to do something classy , but stick to the dark colours , maybe either sand , stain then varnish the existing decking and steps , or replace with cedar or similar , again varnished . More effort , more cost , but will look better , and add value IMO .

You could even add some upright battens the same timber / stain -- it will help break up the gorgeous black haha . . . .

It's hard to improve on gorgeous ( don't I know that ! ) but there you go . . . . . .

It is hard to improve on gorgeous ❤️

Looks great