I would not worry about the color of the addition. You don't have to match it. If this is the original siding, be prepared once the comes off, for some unpleasant surprises. Another reason the focus just on that area, I have seen a few buildings in my town with the same color brick paint the wood sections a tan. It looks far better than the usual white. Also tan would also look good with the new white windows But you HAVE to focus on the trim, fascia and siding of the upper part of the main building. Rotting wood lets in rain water, invites insects and rodents. I would be concerned that the new window in the attic is properly flashed after the new siding is installed. Is cement fiber board used in your area? Siding and trim can be ordered pre-primed.

It's a great house. These 'shed' houses look best to me monochromatic- I would paint everything (except the stone) Sherwin Williams Black Fox or Urbane Bronze. When you can afford it the deck handrails could use updating ( I would replace some sections with stadium stairs and others with glass). Otherwise punch up the landscaping a bit and you are good to go. The pine next to the house is so pretty, I don't love the cedar between the garage and the entrance, it looks like it is in the way?

I have a south-facing house, colonial style, with a cedar shingle roof. I am painting the exterior BM Newburyport Blue (classic navy). Not sure if I should go bright white for the trim, or something slightly creamier. I get overwhelmed with white choices. My house is on a lake, if that makes a difference. Thanks in advance.

The only way to be able to tell which color is best is to sample. I think you have some good possibilities, so either paint some boards or paint large samples on the walls of the house. Be sure to use two coats when sampling so you are replicating the finish as it will be. If you're going to use the color on multiple sides of the house, be sure to look at it on all sides, and at different times of day. The quality of light can drastically change the appearance of a color.