Blue

• Pastel or sky blue makes an attractive house color when the roof is a dark or medium gray. The blue and gray combination is especially attractive on a cottage-style home since parts of the roof are angular and will directly contrast with the front and side of the home, easily displaying the two colors. A modest shade of blue with gray tinges looks good with a gray roof as well; it gives the home a uniform look while showcasing a subtle hue that makes the house appear a little larger.
  
  

Yellow

• Bright shades of yellow are ideal if the house has a dark or charcoal gray roof to create a pairing of bright and neutral color. Pastel or light lemon yellow siding adds a little more refinement to the whimsy of a vividly-colored home and complements a slate gray roof exceptionally well. Adding gray accents to the front of the home, like pillars made of gray stone or a dark gray door, will help to further balance the colors and add sophisticated style to the warmth and happiness of the yellow hue.
  
  

Black or Dark Gray

• A house painted an ash-like black shade or a darker shade of gray than the roof is sleek and modern. You can offset this monochromatic look by painting the front door a striking shade of red like ruby or cranberry to add a pop of color that will make your home one of the most attractive on the block. Further enhancing the gray and black scheme can include painting the door a charcoal gray when the brick or siding is a lighter shade or adding black shutters to the windows as a complement to the gray theme.
  
  

Muted or Medium Red

• Gray and red look good together because they are the combination of bold and understated color. A muted shade of red like a blush or intense pink is visually appealing for home siding and bricks and can even make a medium gray roof more noticeable. A more intense red like cherry will stand out on a house with light and dark gray bricks and a charcoal gray roof. If the entire house is painted red, off-setting the color with shutters and a front door in a blackish shade of gray is elegant but eye-catching.