What are the connotations of the color of the wrap Blanche wears when she speaks to Mitch outside the bathroom?

In context, the color red is associated with love and desire. In the scene where Blanche is speaking with Mitch outside of the bathroom, he has just learned about her past. The red robe serves as a symbol of desire, Blanche's desire to attract Mitch and marry him.... her desire to make him forget about her past.