The iota Center is the main spot dedicated to “The dream of creating a color music for the eye, comparable with auditory music for the ear, dates to antiquity…
http://www.iotacenter.org/

and for Mary Ellen Butes Site there:
http://www.iotacenter.org/program/publication/bute

an interetsing link with a lot of texts to the topic: http://www.centerforvisualmusic.org
especially:
http://www.centerforvisualmusic.org/Library.html

article by Christine Lee Gengaro on Fischinger and Bute: http://www.usc.edu/libraries/partners/resonance/2006/Spring/gengaro/

light as a medium is covered in the current issue (39) of artcrush see:
http://www.artkrush.com/mailer/issue39/index.html

about the history of women in informatics – german website:
http://www.frauen-informatik-geschichte.de/

One more link to lichtmusik:
http://www.roberthaller.com/firstlight