A wall test involves a bit of an investment in time and money, but will be well worth it in the long run. Buy a quarter can of each color you’re considering, choose a wall in the room you’re going to paint, and go to work. Take down all pictures and art, move the furniture away from the wall, and apply a good-sized sample of each color to the wall. Remember colors look different when dry, so don’t make any snap decisions. Also note that the colors will change in appearance as the light in the room changes, so you’ll want to live with the samples for at least 24 hours to see each color at various times of the day.