difference between green and white papers

Green paper - discussion docoment - White paper voting version in the House
https://uk.answers.yahoo.com/question/index?qid=20061006061924AAyNoKY

White is the last one before official announcements and green is earlier on along the planning stage (the first draft proposals?)
@ anlogy is green when it is young stage. Then it grows old and hair turns white. Thats the final stage.