 To create the eerie nighttime feeling, the background painters used  dark paper instead of the traditional white. This also allowed them  to save time from painting large portions of black color as most of  the scenes are set at night. The animators coined the term "Dark  Deco" for this art style.  Since the debut of this series, various elements have been adapted  into the regular continuity of the Batman comics. These include the  series most popular original character, Harley Quinn, and the  shows origin for Mr. Freeze.