They relate mostly to elevated states of consciousness. Ajna is the center of psychic powers and can produce many psychic effects. Meditation on ajna is said to cure nervousness. It is referred to as the thousand-petaled lotus and corresponds with astral projection and enlightenment. There are also many minor chakras throughout the body.
Some occultists prefer to describe the magical elements as tattvas according to the Eastern system.
Notice that these symbols and colors are generally different than the western symbols and colors for the elements. It is a physical or mental discipline designed to condition and invigorate the mind and body. This is a much touted area of the occult. There are many meditation techniques, and many claims made for the benefits of meditation. Most kinds of meditation are the concentrative type.