Spiritually it is the color of wisdom and connects us to our mental self.
Yellow is sunshine.
It is a warm color that, like red, has conflicting symbolism. On the one hand it denotes happiness and joy but on the other hand yellow is the color of cowardice and deceit.
Yellow is one of the warm colors. Because of the high visibility of bright yellow, it is often used for hazard signs and some emergency vehicles.
Yellow is cheerful.
Yellow is for mourning in Egypt and actors of the Middle Ages wore yellow to signify the dead. Yet yellow has also represented courage (Japan), merchants (India), and peace.