I would do posts & gutters in the charcoal (darkest one) & fascia in a lighter tone grey to match the roof. The posts & gutter would disappear & brick work would become the feature along with the roof

What ever colour you like is what you should go with - I have a black roof and a white house and white down pipes and guttering - the plastic type. All I notice is how dirty is looks when the winter has set in and been and gone and you are left with green mildew on the guttering and down pipes. If I have a choice and it suited my house I would go for a dark colour - however if you are going to tin you will want colour steel as the sun will just bake black or dark paint. Also look at the life time warranty of both the plastic and steel to determine which may last longer and be cheaper to fix longer term.

Thanks swich5 - I don't want a domestic either (and I liked the dark colour too so I'm just rolling with it! If it is hot in the summer I'm hopeful it will make it warmer in winter...?) BTW, a friend of ours has used Surfmist Colourbond for her roof and as a feature on the sides of her house and it doesn't look coloured or creamy - comes out very neutral, more a very pale, weathered galvanised iron sort of grey, and might work well for your roof. Good luck!

@Dee painted fly screen door up now. Still haven't painted concrete stairs and verandah.