Gold is the color of hidden knowledge and wisdom, it is inner knowing and profound understanding. Gold is the symbol of riches on all levels. Gold is power and strength. Gold is given as a mark of status - from 'gold stars' at school to the crowns of kings and queens. It is associated with spiritual power and holiness.
Silence is golden.
We talk of 'going for gold' when we are aiming high. Gold is a color of dignity and might. Gold is an excellent conductor of heat and electricity but it is resistant to chemical reagents and is, therefore, virtually incorruptible. We refer to things that are rare and that have a high value as being like 'gold dust' and we describe someone who is generous and pure as having a 'heart of gold'. Yellow is composed of a single ray in contrast to most of the other colors which are secondary or tertiary colors.