The window trim change would be to Craftsman style. Unless you are doing the work yourself it seems a lot of expense for little difference on upstairs windows. It would, however, be extremely easy to do on your front door as you would only need to change the top board. And you could replace the side lights with solid wood inserts, or you could use textured glass that would obscure the view while still letting light in. While the limestone exterior is very light it has a yellow hue. Simply speaking the easiest way to find colors that work with the warm limestone is to choose a nearby color. That was probably why the trim is green. Since you prefer a modern look, I suggest you keep your siding light and use color only in the trim. Below are two combinations that I like. I darkened the roof color in these pictures.

I don't know where you live, but have you checked Weather Shield Windows. They have aluminum-clad wood windows that would look great on your home. Bronze windows would be great on your home https://www.weathershield.com/Product-List/Weather-Shield-Contemporary-Collection They are a national brand and you can get competitive pricing. Replacement windows are typically a huge rip off to the consumer. , I'm not sure I would consider vinyl windows for your home. Thicker frames, less glass typically on vinyl. I have personally never heard of Simonton Vinyl Windows. Have you bothered to check Andersen or Jen Weld from your local big box store?

I'd confirm available colors in each brand before making a decision - we were going to go with Mission Brown, which per the website is available in our area, but due to Covid, they had reduced their colors down to a handful. This was 4-5 months ago so things have maybe changed. Good to know before you get your hopes up as we did. We ended up with Weathered Wood and we like it a lot as well. Before: After Good luck!

Charcoal brown roof, golden taupe on the non brick, and the garage door. Paint the front door a light turquoise. (Or find nice Adirondack chairs in a turquoise and paint the front door the same color.) Dilute whatever color you pick for the siding to very, very light shade of it to paint the entryway. Get a nice shed for mom and paint it the color of the siding. Something like this but a little more "taupe-y" since you have gray grout and some black patterning in the brick. Those bushes aren't doing the entryway any favors. In fall, cut them down about a foot.