A few years ago I went wild and decided to paint focal walls in our house for highlight and mood. My husband designed and built three custom homes for us over the past 35 years so I am lucky to work with really "good bones" so to speak in terms of architecture. It's hard to gauge (how dark- how light) to go on a large surface but we are really happy with the results. During the day the light changes and you get alot of variable moods (it also makes it hard to photograph and get the colors accurately)! I am also thrilled at how the colored walls set a dramatic background for artwork. My kitchen and breakfast room are bold warm colors that start my day off with energy, while bedrooms are painted with cool, softer colors. I realized this winter how important to me color in the home really is- it does affect your mood and creativity - and if your are able to do it- I say go for it!