Do you go in the roofspace at all?
What is the house like?
I only said colourbond because it's cheaper and if you're building new, will generally make a much more modern look.
If you have a character house tile may be the way to go... I personally don't like tile roof and I think they age poorly unless terracotta.
And if you go colourbond avoid blue because it ages the absolute worst of the lot and you'll be kicking yourself. As for colour/heat relationship, if you don't go in there it won't matter. A colourbond roof will have 80mm insulation between battens and sheet, possibly as well as on ceiling joists, blocking alot of heat; a tile roof may have no insulation at all (depending who does it and how much it costs).
At the end of the day, anything is possible if you want to pay for it. Work out what's most important to you (it's your house, so love it).
