Colour visualiser tool. Try shale grey and Wallaby roof on it. The blue they show on the garage is deep ocean, one of colorbonds Classic colours. Too dark for roof anywhere that gets hot. To match a fence to that blue, try Colorbond bluestone. http://alcoil.com.au/inspiration/colour-visualisation-tool/?roof=7F7C78&roof-type=tile

I just googled & found this site, which quotes cost of R2.5 75mm. there are other suppliers as well. What was quoted to you for cost of roof installation, and was it itemised so you can see exactly what thickness the foil-backed insulation builder will use? I'm guessing the thinner (lower R factor). So, the new quote should reflect a credit for the cost of previous insulation, since it won't be used, then cost of thicker insulation added. Does that make sense? If you are unsure, best to speak with the builder. https://www.pricewiseinsulation.com.au/product/heavy-duty-fletcher-permastop/

Were using Colorbond monument Matt on our project. I don’t think it is actually a different colour to the standard Colorbond monument but your eye perceives it differently so it looks darker. I’m not sure if that helps with your decision making though.

If this is a cubby house, please do not choose a black roof. The poor children will be roasting inside in summer. Choose a lighter colour. I would be asking how the occupants of the cubby will be lasting in the long hot summer not the colorbond roof.