To most Pagans balance is essential. One method of remaining or regaining balance is to work with the chakra system through means of meditation and working with stones. The basic meditation is to go into a meditative trance and to focus upon opening a vortex (or "whirlpool") of that chakra's corresponding color, going from base to crown. This should be done while focusing upon balancing the properties of each chakra center. Do this with each one until you are intuitively satisfied that it is properly balanced. Once you have completed this process you should begin again at the crown going toward the base, this time visualizing the vortex as closing back to a smaller size so that they are not left wide open. If you have difficulty with the visualization of a vortex/whirlpool, you may want to try visualizing it as an appropriately colored rosebud spinning open on the way up and spinning closed on the way down. To add the use of stones, I simply place the appropriate stone upon it's corresponding chakra point on the physical body as I lie flat.
The crown chakra's associated color is violet, and it's stone is amethyst. It represents the highest form of spirituality, connection to the divine, as well as connection to humankind.
The third eye, or brow, chakra's color is indigo and it's stone is lapis lazuli. It represents perception, especially psychic perception. It is generally the most active chakra during ceremony and ritual activity as well as astral projection and all other forms of psychic work.
The throat chakra corresponds to the color blue, and my preference for stones for this chakra is blue sapphire. Being closely associated with the vocal cords, it represents communications. However, this chakra is not limited to verbal communications but all forms including body language and behaviors which communicate ideas to others.
The color of the heart chakra is green, and I like to use emerald with it. It relates to feelings of all sorts of love, especially universal love. It deals with qualities of expansion and harmony with others as well as the self.
The solar plexus chakra is considered to be yellow, and the associated stone is citrine. It governs mental activities including thought as well as more abstract processes such as creativity.
The sacral chakra is orange, and it's stone is carnelian. It is associated with our drives and more basic issues of survival.
The base chakra is red, and I use ruby for this one. This is the chakra which keeps us rooted in the everyday, practical, mundane tasks at hand. Where the sacral chakra deals with issues of survival (such as how to obtain them), this chakra deals more with letting us know what is actually needed and driving us to obtain it.