Many mystics and yogis have written and taught about chakras and the rising of the kundalini. Bringing the energy to the crown of the head is the physical counterpart to achieving enlightenment. There are many approaches to awakening and raising the kundalini. A French physician and scientist, Dr. Francis Lefebure, even designed a device called a Gyrascope that would “awaken” the kundalini when used for about an hour a day.
As the kundalini moves upward, the energy flows through seven major energy centers called chakras. There are seven major chakras, but there may be many more energy centers in the body. Some systems include eight (adding the secret chamber of the heart) and other systems include twelve (adding five secret ray chakras in the hands and feet to the fundamental seven). Other systems break this down further into 144 chakras or more.
The colors associated with the chakras also differ in various traditions. Many systems use the colors of the rainbow. Others use a sequence of white, violet, purple/gold, pink, blue, green, and yellow, beginning at the base and moving up to the crown chakra. This second set of colors are purported to be the purified colors of the chakras or the chakras in their etheric state.
There are a number of ways to understand and work with the chakras. Among these are the toning the seed syllable or primordial sounds for each chakra; chanting mantras dedicated to the deities associated with each chakras; visualizing light and healing for the physical organs associated with each chakra; working with the psychological and emotional aspects of each chakra; using visualization, art (yantras) and color therapy; and the use of essential oils, natural elements, and healing stones.
There are differences in recommendations from source to source for some of these approaches. Research and personal experience will help you to determine which tools are most helpful for you.