When you paint, try to create the same sized (larger is modern) white trim all the way around the windows. White doors and trim. Pick a medium tanish/brown from the shakes for the field. You could do black doors with this combo as well...

This subject has come up before. The Houzz experts have said it is very expensive to try to reframe a mansard roof.

I think you need to interview some roofers in your area to find out what is available. I do not mind your current shingles but I suspect you would be happier with something less bulky.