Has anyone mentioned Scriabin?

Also worth a mention:

   Music of the spheres and the dance of death; studies in musical
   iconology.  / Meyer-Baer, Kathi, 1892- / Princeton / 1970

   Sound color. / Slawson, Wayne. / Berkeley / 1985

   Brian Eno: his music and the vertical color of sound. / Tamm, Eric,
   1955- / Boston / 1989

   Color-music. / Karwoski, Theodore Francis, 1896- / Columbus, O. / 1938

I know only the Meyer-Baer, which I read many years and recall it was quite
fascinating.

Karl