What was I thinking? Years ago, while repainting some rooms, I decided to wrap the wall color all the way up on to the ceiling. Not only in my bedroom, but in the guest room, the rec room and my daughters room. It added warmth and coziness to the rooms and was easier than taping off the walls for crisp line between wall and ceiling. Many decorators refer to the ceiling as the 5th wall and paint it accordingly. This can be beautiful, especially if you have crown moulding to highlight.
Heed my warning, don't do it! One day you will want to change the color of your room. You will then have to change the color of your ceiling. Painting a ceiling is tough, it is messy work and hard on your neck and back. Flat white ceiling paint may not be the most imaginative, but it will bounce light and will always look clean and crisp. Save the creativity for your walls. Painted ceilings? Crisp, clean, flat white paint is the way to go.