The Ritual Use of Colors
For many years now, it has been very easy to find various writings about the ritual use of colors. It seems evident that colors constitute a very old knowledge which was associated with ritual practices from the very beginning of the use of rituals. It is easy to imagine that there must have been a good symbolic understanding of the use of colors in ancient Egypt, but proof of this is very rare in the old texts. In ancient writings, few colors (such as green for example) were really linked with a precise idea, such as, in this case: rebirth.
Long before the birth of Qabalah, earlier authors (such as the byzantine writer Ioannis Lydi) began to write about the symbolism of colors. He related colors to days, planets, and Divinities, and he explained the mythological origin of these relationships. Yellow became the color of Venus because of the color of her hair, Gold for the sun, etc. Following in the Hermetic tradition, the Master of the Golden Chain, Marsilio Ficino (Florence, Italy, 15th century), wrote extensively about the use of colors, music and perfumes in rituals. You can see aspects of this tradition in the occultism of the 19th century (Eliphas Levi, Papus, etc.).