Blue reduces stress, creating a sense of calmness, relaxation and order - we certainly feel a sense of calm if we lie on our backs and look into a bright blue cloudless sky.
It slows the metabolism. The paler the blue the more freedom we feel.
Blue relates to one-to-one communication, especially communication using the voice - speaking the truth through verbal self-expression - it is the teacher, the public speaker.
The color blue is idealistic, enhancing self-expression and our ability to communicate our needs and wants. It inspires higher ideals.