What do the various colours represent?

In iconography and church adornment, there is a prolific use of colour. Each colour is representative of something. 

Black - Symbolises death. The black cassock therefore symbolises the priest dying to the world; that is, to selfishness.

White - Symbolises resurrection. The white tunic represents life.

Blue - Symbolises heaven or divinity. Think sky.

Red - Symbolises the earth. Think blood or dirt.

Green - Symbolises new life. Think budding plant.

Purple - Symbolises royalty.

Gold - Symbolises Christ.