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.
To pick the right color for your space, grab lots of paint chips, place them on the wall near the trim, and look at during different times of the day to see how light affect the color. When you’re ready to start testing shades, paint sample colors onto sheets of heavy paper instead of the wall so you can move them around and not make a mess of your walls. 
The graph says the average cost to paint a home interior is $1600; at the high end, $4,000. But for what size home? I'm getting estimates for painting an 1800 square foot townhome in the range of about $6500 - which includes sanding and repainting all doors, and painting all trim, walls and ceilings. What does the range above include and for how big of a home? Thanks.

Home Interior Painter