There is a comprehensive guide at the Bluescope website at http://www.steel.com.au/products/coated-steel/colorbond-steel/basix-and-bca-classification

We want something that blends in, but because it's a zinc and colourbond shed home, I want to choose a colour that makes it look more like a house and less like a shed. I was looking at basalt but my husband would prefer a lighter colour for keeping the place cool in summer. My original choice was windspray but I'm a bit concerned it won't contrast enough with the zinc roof...but perhaps better than dune that might look too 'sheddy'...so hard to decide!

Yes, your front winodw is really letting your house down. It looks like a cheap. aluminium window that was added inthe 1970's to enclose a front verandah to make it a sunroom. If you need the sunroom then I would replace it with a white painted timber window to match the original style of the architecture, then finish off with the landscaping. Or you could reinstate the verandah. Your two-tone brickwork and terracotta tiles roof already has quite a bit of colour, so I wouldn't be introducing a contemporary greige into such a classic elevation. Celebrate what you have and work with the existing style. Best of luck Dr Retro of Dr Retro House Calls

Are you sure that they are terracotta roof tiles? They look like concrete tiles to me. If you look from underneath (in your attic) terracotta tiles are clay orange underneath, whereas concrete ones are grey. If they are concrete tiles then paint them. If they are terracotta tiles then leave them and paint your awnings to match. Painting your awnings to match is easier and cheaper than painting a tiled roof. Best of luck, Dr Retro of Dr Retro House Calls/Dr Retro Virtual Visits