All spiritual traditions have used colour in magic and for any one colour there may be many physical and emotional associations. These do not change much across the different spiritual communities. Popular examples include the colours red and pink being used to portray love and affection; green, red and gold to denote winter festivities; and white to show peace or purity. It is not surprising that colours have found their way into mystical oils and potions.
Most commercial oils have artificial colours added to their mixtures. Some manufacturers of fragrance oils, commonly used to make mystical oils, already colour their product to mimic the natural colours of the essential oils they are designed to smell like or to portray the plant from which the name comes. The occult manufacturer may then even add additional colour according to their traditions and formulae.
The principal colours are achieved by natural means if pure essential oils are used, as they should be, or by adding certain natural colorants after mixing. A green colour can be achieved from oil soluble chlorophyll, an extract of leaves or alfalfa; red colour from dried beetroot or alkanet; and yellow colour from annatto, saffron or turmeric.
The colours used in mystical oils are generally based upon the planetary associations of the oil. Oils for control and domination are normally red, which is associated with Mars (war and aggression, or action); but oils for fame and wealth are yellow in colour as they are associated with the Sun (fertility, intelligence and splendour). The colour of the oil is meant to enhance the psycho-spiritual experience of its user based on established understanding of those colours.