If you go charcoal on the shakes you will need gray /black roofing and the siding around the paladian infill windows in the screen porch wants to match the charcoal above with black frames happening .. shifting from the earthy tones you have now may not be ideal with this brick .. it appears historic, faded, with a terracotta undertone to it . . . You might consider a darker desert green brown / camoflauge toned neutral so as not to create so much contrast and clash .. or try an olive gray like bm equestrian gray for siding and weathered wood roofing tones . . .. .not sure the black roof and frames are going to advance the historic / tudor ish feeling of the house .. . its a bigger transition than you may have planned - downspouts and other penetrations now in earth tones will all need to be addressed .. .