Throughout his "Triple Threat" Tour, Prince
was often seen writing in, what legend has it, was a purple notebook.
In the spring of 1983, he and William Blinn began work on a screenplay entitled "Dreams".
Blinn and Prince would send their revisions back and forth to each other while Prince was on tour. One of the things that Prince wanted was that the word "purple" be in the title and the seeds that would one day become "Purple Rain" were planted.
The original script was a much darker story revolving around The Kid who was torn between life (i.e; gratuitous sex scenes and dynamic live performances) and death (in this version of the film, The Kidís father murders his wife and then commits suicide).
As a result, the original version of the script had to be lightened up some to get the "R" rating from the X rating they would have given the original version.