I too love the idea of a dark gray house with white or ivory trim but if you are attracted to lighter combinations those will work too.
Tan house with dark roof.
Use rich exterior house paint colors with a touch of sheen to give your home been around awhile character.
A soft muted brown or the right color grey are your best choices.
This contrast needs something to help bridge the two colors given the classic design of the architecture.
There are no surprises here no drama and no pops of color.
Instead you have a peaceful appearance that blends in perfectly with the style and architecture of the house.
Grey brook 5001 1b valspar.
Yellow with a strong brown roof is a very common mistake.
These are perhaps the trickiest color to work with.
The spicy red highlights the roof peak outlines windows accents the front door and defines the porch trim.
This is a popular choice and almost always bad.
This is done by using a classic white trim and white shutters that can help keep the siding light while also adding a cool toned touch to tie in the roof.
You can also choose to incorporate a mix of colors like gray and black or tan and brown shingles for a staggered effect.
Tan shingles with a tan house.
To be honest i would choose a tan if you had a brown or even a black roof but i think some of the colors that lefty has suggested would work better and look more interesting with the pewter gray roof you have.
White pops up as window sashes to bring dimension and brightness to the facade.
Black can be too harsh but will work in limited situations.
The roof makes up about 40 of the visible exterior of your home depending on the style of the house so choosing the right shingle colors and roofing materials means that when you make your choice you are also deciding on the type of first impression you want to make with your home and even bigger decisions like the resale value of the property.
For a contrasting pop of color opt for reddish orange shades or lighter tan colors.
While the siding is a light warm tan the roof is a darker cooler gray.