maybe add some brightly coloured planters and flowers around the front of the house and yard to give it not-so-permanent colour. You could add something like and over the garage door pergola like this one and maybe a brighter coloured front door.

The only windows you have that a suitable for shutters are the two above the garage and the one on the porch. This article on shutters may help with the decision. I think an ornamental tree out in front of the double window on the right would help - maybe a dogwood. A pair of Japanese maples flanking that window would do nicely too.
http://www.lifeofanarchitect.com/residential-architecture-101-shutters/

Your home is beautiful as is! I love the clean look. Perhaps some brightly colored flowers in planters or even a welcoming red front door if you feel it needs a little something.

Add some great lanterns on either side of the garage.

Your house is gorgeous with classic clean lines; a designer/builder dream! All you need is some more mature plants (yours are very small). Add some flowering vines to climb your porch posts and try some potted plants in bold colored pots on the porch. Use plants with variegated leaves and bright green colors that will provide contrast against the dark house. Doing that will create interest and will give it the charm you're missing!

I love the clean lines. I Echo some of the others with some bright pots and flowers- perhaps in the landscaping as well- and if you want contrasting bright door! Beautiful home!

Oh and some uplighting in the landscaping would look beautiful at night!