I think a light grey would look very smart - white trim. Be sure to paint the garage door the same color as the house to help it disappear.

Rosemary, try doing a large paint sample to hold against your brick to see if it works well in the shade and sun. You could prime a piece of scrap drywall and paint two coats on it. Glad to hear you are considering a greyish roof instead of the red tone!

What is the color of the cabinet (it's hard to tell in your photo)? I painted my living room Classic Silver from Behr paints. It's a beautiful, medium colored silvery gray that looks great with about every color. You could look on Behr's website or any other paint website, and virtually paint a living room. That should give you an idea how the color would work but I also recommend buying paint samples first before buying enough paint to paint the room. It will save you frustration, time, and money. Before choosing the Classic Silver, I purchased two other gray paint samples along with the Classic Silver, painted large enough sections on my living room wall, looked at the paint colors for a few days before making my choice. I made sure the color worked well on sunny and cloudy days.

This is Agreeable Gray, Extra White and Gauntlet Gray. I actually think it would be a mistake to go too much gray on the body. You will already have a gray roof. Canvas Tan is a little grayer than Patience. I would not use those garage doors shown above. They are a modern design and your house is closer to traditional. I also think the wood grain and side windows when combined with stone would look too busy. I hope one of the professionals will speak to the door as I am just a person like you. What is the name of your HOA? Stay away from Unique Gray. It is lilac color.