This is one of the interesting project from Goldsmith University, the RSVP game with Neurosky headset.
Here is a chart of the seven chakras colours and audio frequencies.
This is the website of the book, New Brain, New World by Erik Hoffmann, which includes information on EEG, meditation, etc.
In a reference reading, Brain Mapping: A Short Guide to Interpretation, Philosophy and Future, by Eric R. Braverman, M.D., it summarizes the following,
The Nerosky EEG band frequencies information is available here. In summary,
Terence W. Picton has written this introductory text on electroencephalogram (EEG).
Neuro Gadget is the first information website dedicated to brain computer interfaces, biofeedback system, etc.
Axio is another startup company working on brain computer interface as headband.