Thanks for all the advice and kind words. I do think I am more and more set on a deep, matte green. As far as shutters go, yes - I like that very dark green that looks almost black but not quite. The house is sort of a saltbox style, so we have a TON of roof - one estimate this week quoted us 2800 s.f. of roof area - so the vast expanse of red is a lot to look at. I think green would blend in a bit better to the trees, etc.
If anyone has recommendations for a roofer who works in the Washington, DC/mid Atlantic area and specializes in histroic houses/metal rooves, please speak up!
For Kurt's questions - the house was extensively renovated in 1980, and I think a few fireplaces were covered up. There are two left but both work well. I grew up in a 1742 house in Connecticut where we had 6!