How about cream, a lighter green, and a midtone sandy beigy brown. Make sure the lighter green doesn't tend toward blue like teal green, but is a true green. A dusty rose or mauve may go too. After all red is the complimentary color of green. Not that you'd want red, but if the colors you pick have a hint of red or pink they would probably go. I would take your ball of wool into the shop and pick out colors you would wear with the green if it were slacks. lay them out and see which goes together. I would definately include cream to lighten up the dark green.

I did a quick google image search and the colors were named: Polo Mallet White RL1051 by Ralph Lauren for the siding and you already know the shutter color: Benjamin Moore Evening Dove 2128-30 Here is the match to that Polo Mallet White RL1051 color in this link: http://www.myperfectcolor.com/en/color/23163_Ralph-Lauren-WW05-Polo-Mallet-White I didn't find the trim color. Maybe one of the others will know it or give you an idea of what it might be. You would have to sample anyway to get the right combo Congrats on finding clapboard in good condition under your vinyl siding :)

your ideas look great. The white trim should go. Definitely break up the 'soldiers at attention' landscaping, especially with an interesting tree/ shrub on the right side, between the windows. I'm a big fan of ornamental grass, but caution -some do grow quite large, so research them, your zone, size etc. Another is a tree- Harry Lauder's Walking Stick. Very gnarly, architectural, quick growing- but can get large. Nice homestead! Good luck.

Post pictures of your space .