If you want to duplicate a playlist, select a playlist and click with the right-click on the three bars on the right side of the corner. An another tab opens where you have the opportunity to select "Duplicate". So you can make a copy of your playlist here. If you click on "Duplicate", the copied playlist appears in the playlist overview.
(see and link under "Nested Playlist")
You have the option to label your playlist with a colored label. To define a label for your playlist please follow the next steps:
Then your playlist will be labeled. With a variety of different labels, the colored markings provide a better overview.