Working with what stays
Keep the dormer tied to the body
Try the dormer walls in the principal siding color first. Its position above the facade already creates emphasis; a separate accent can be compared later if the roof composition needs it.
Use the porch bases as material anchors
Brick pier bases and the chimney remain visible beside the paint. Judge deep blue, green and greige with those warm masonry sections in view rather than using a siding-only example.