Blue will purify your thinking, so you can cut through the clutter and discover what is most important in your life. It helps you integrate the big picture with the little picture. Blue is an important colour in interior design theory and it affects the human mind profoundly. There is a reason why blue is the perfect colour for bedrooms. It instils a sense of serenity and peace and can be a very soothing colour. This cool, quiet and reserved colour can also represent formality. It is best when paired with white or other lighter hues.