Color is more powerful than you think. It plays with your emotions without you even realizing it (subliminally).
How do you feel when you wear the color red? Most people feel powerful because red is a power color.
Purple suggests royalty and creativity. Purple also happens to be my favorite color! Purple is generally not an appropriate color for walls in a house.
Black can either be dark and stormy or mysterious or sophisticated, depending on where and how you use it. Black is used in advertising quite a bit, but painting walls black is better left to your teenage son who is going through a phase. Be aware that if you paint over black you'll need to buy extra primer!
When it comes to selling your home, you should realize that the colors you paint the walls have great bearing on potential buyers that walk through your door. This room has a feature wall with a splash of color that looks bright and springy:
If they had painted the wall the same color as the rest of the walls in the room, it may have turned out looking stark, like this:
However, the stark look is trendy right now, as evidenced by many of the homes that are being shown on television currently. In my own opinion this room could use a colorful abstract painting and some matching pillows and rugs to make it feel more "homey."
Color is subjective, so if you are selling keep in mind the type of buyers that would be interested in your home and what their tastes are.
Just for fun, here is a quiz that will tell you what color you should decorate with based on your personality:
What are your thoughts?