A neutral palette with occasional bright accents is the core of modern exterior paint design. Your exact color choice will depend on your area, because surrounding colors and natural light can make a big difference in the way paint colors appear. Get several paint color cards in your preferred color range and hold them up to your home's exterior in daylight to find the one that best suits your exterior.
It sounds a bit more interesting than beige, and in fact the pale brown tones of khaki do have their own look. A light tan with yellow undertones, khaki provides a neutral yet warm look that is well suited to both urban and suburban homes. Accents of rich earth tones can make good trim and door colors, such as brick reds or chocolate browns. For a lighter look, offset your khaki paint with bright white trim. Choose a shade of khaki that does not have too much yellow in it if your home is surrounded by grays or greens, as these can make the yellower tones look sallow. If you find khaki too neutral for your home, dress things up with brightly colored flowering plants to attract attention in a natural way.
Grays are anything but drab when you choose the right shade and combine it with the right trim color. Stone-hue grays work well for almost any house style. For a clean look, try bright white trim that can give your home both a modern and classic feel. For a bit more modern flair, pair your gray siding with plum trim or white trim and a bright plum door. Grays with a bit of brown in them work particularly well with blocky modern architecture, lending a bit of earthiness to an otherwise unnatural shape.
Mid-tone blues that tend toward gray are an excellent color choice for modern homes. Accent architectural features with a lighter shade of blue, then brighten the look with white trim or go modern and chic with rich, earthy brown trim and a white door.
Go a little bolder with your modern home by choosing a sage or grass green tone that is earthy and subtle. Contrast the green with a plum or dusky purple for the trim, and then select a paler green or white for other accents, such as the door. Dusky blues also can work well with green tones in place of the purples.