When choosing completely new colors for an exterior I recommend that you drive around and look at homes to see what appeals to you in real life. Are you planning on painting everything or just the siding?

Your mock up looks pretty great.

I'd paint the foundation, too, unless you're planning foundation plantings, which I recommend.

With brown, I'd go with a cream for the trim and shutters.

Your dark brown looks as dark muted green on my screen that looks very good.

You have a lot of dark trees behind your home. I don't think I would paint a really dark color.

I would probably paint the lower portion one shade darker than the house and the garage door one shade darker than the foundation.

Then I would add some nice landscape.

In theory I love some of the dark painted homes, but all too often when I see a simple home painted the dramatic dark colors withoutout enough interest they end up looking like a black box.

Even some of the nicer, more interesting homes still disappear when they are too dark

without the interior lights this would be a black hole.

Keep in mind that dark colors will cause the house to heat up more in the sun. According to the second photo you are in Missouri, so i would stick with light colors.