rouge my knees and roll my stockings down: put pink makeup on the knees, which are exposed by the rolled down stockings. Prior to the 1920s, women's fashions covered the knees. Daring women called flappers began the fashion of showing them, which was considered super-sexy at the time.
gotta love the internet. did a google search and found this page
http://slangcity.com/songs/all_that_jazz.htm#1
guess it was just before our time