Our new house will be well insulated using cellulose and will have a metal roof. I am wondering what difference (if any) the colour will make to heat absorption/reflection? We would like to go for a charcoal coloured roof but would this create problems in the Summer? We live near Montreal so it gets pretty cold here in the Winter and fairly hot during Summer.

Muellier(muellerinc.com) has reflectivity/emissivity numbers for their various colors posted on their website.

I am wondering the difference color will make to heat absorption/reflection . We would like to go for a charcoal co loured roof but would this create problems in the Summer?