Aside from snarky comments about vinyl siding always being a "wrong choice"... I assume you're asking about color. Unless you live in a neighborhood with HOA color police you can do whatever looks good to you. Often you might want an outbuilding to be a different color as you look at it from your house, depending on whether you'd like it to stand out or blend in with whatever's behind it in your field of view.

Will the detached garage be visible from the front or completely hidden? To me that makes a difference. If it is visible from the front of the house, it is better if the two sidings match in material, style and color. If it is completely hidden from the front, then having a coordinating vinyl works IMO.

I like #5 for the siding, and the Mahogany for the garage doors, because they complement the brick well, but that gray roof does not play well with any of the color options.

You are right a bit different than what is the style now but IMO for a small area I would try to match it. I also suggest you get rid of those shutter they do not belong on those windows I assume you are painting the old siding so yes to making the addition the same color for sure even if you do not match the old siding.As for not signifigant architexture this is a aMCM ranch and IMO very much signifigant . I ahppen to love MCM ranches and they can be awesome in style so make sure that garge is the same style .Can i aslo see the new windows please . Just post here inanother comment do not start another post.