Keep in mind that color can impact the way a room appears in many ways. Light colors may help brighten a darker space. Cool colors will recede visually from the eye, and make a small space appear bigger. Warm colors contract visually, which can make larger spaces appear smaller or more cozy. Combining cool and warm tones in one room - like with accent walls - can visually change the shape of a room, making rectangles look more like squares.
The color scheme that is chosen for the home creates the initial impression that an individual has of the premises as a whole.  Whether complimentary or unflattering colors are selected, the house will gain an identity of its own when the paint is applied.  There are many times that a homeowner misses opportunities to accentuate positive attributes that the home has to offer by failing to choose the best exterior paint colors. 
Once you have the approximate square footage that you’ll need to paint, remember that a gallon of paint generally covers between 250 and 400 square feet. You’ll need more if you’re painting a rough, porous material, or if you want to paint a dark house a much lighter color. Depending on your color choice, you may need a more expensive tinted primer to help with the color transition. Thornton House Painters