LANE: I’m gonna get a soda, anybody want anything?
LORELAI: Yes, the night of my 14th birthday back so I can right the green-hot-pant-roller-disco outfit wrong.
A roller disco is a skating rink where the dancers wear roller skates to move to disco music (or any modern dance music). The concept originated in the 1970s and peaked around 1980, although they are still held now as retro entertainment.
Lorelai’s 14th birthday was in 1982, so she was already slightly behind the trends when she chose her roller disco outfit (it actually fits better with Amy Sherman-Palladino’s 14th birthday in 1980). It’s not clear whether her birthday was celebrated at a roller disco, or she just thought it would be a good outfit to wear to her party. Let’s hope the first one.