This blog post from The St.Paul Real Estate Blog written by Teresa Boardman puts it in simple terms. Light helps to sell your home.
Keep it light
I write this same article or one similar to it every year. If your home is on the market or if you are planning on putting it on the market soon make sure it is well lit.
When buyers come to see your home their eyes will be taking in a lot of information. If there is more light they will have a more favorable impression of your home and who knows they may even make an offer.
During the day if at all possible leave the blinds and curtains open. Consider removing heavy drapes and window coverings that can not be put aside to let more light in. If your home is being shown in the evening or on a dark cloudy day leave as many lights on as you can.
You will notice that most builders will ignore some of this years hottest color trends in favor of lighter brighter colors and it is very rare to see a model with blinds or drapes covering the window.
Lighting can help sell a home.