The Colorful Labels management always works in the same way, regardless of whether it is global or in a project environment. In the displayed list, all the labels are shown together with their set color. The trash can icon next to these labels is used to delete them. Above this list is an input field and a color selector to add a new Colorful Label.
The global management for Colorful Labels can be found under the Installed Apps in the navigation on the left. All labels stored here can be used everywhere.
The project settings for Colorful Labels can be found in the left navigation under Settings and then in the "Apps" section. Labels stored here can only be used in this project.