Goethe's work on color and seeing has a complicated history spanning the years from 1790 to 1832. During the years of 1791-1793 Goethe was much concerned with the genesis and evolution of color and color perception; his first published work on the subject appeared in Weimar in 1791-92 with parts one and two of his Beiträge zur Optik [Contributions on Optics], for the most part studies of prismatic light. He planned a further four parts in this series, but the third part, “Von den Farbigen Schatten” [“Concerning Colored Shadows”] (written 1792-93), explaining his surprise discovery of the phenomenon he termed “farbige Schatten” [colored shadows]…
Allert, Beate. "Zur Farbenlehre". The Literary Encyclopedia. First published 23 August 2006; last revised 30 November -1.
[http://www.litencyc.com/php/sworks.php?rec=true&UID=5189, accessed 19 April 2015.]