A Pathway can be in one of the states listed by the Pathway States Extendable Enumeration, and each of these states has an associated color that is used for displaying them in the Butterfly View.
Note: this feature is used in thecentral Butterfly panel, where the color defined for each Pathway State automatically changes, depending on the fill ratio. This is the ONLY place where the Pathway State is visually indicated, meaning they're not displayed in Design World. Click on this link for more details about this feature.
The Pathway State Manager dialog allows managing existing and creating new Pathway States. It is a standard Manager dialog that consists of a data grid listing:
existing Pathway States by their Name,
a column showing the defined Color for each Pathway State
a column saying if the state was User Added or pre-defined,
action buttons for adding, editing and deleting a Pathway State,
and an additional standard Quick Search box on top of dialog for easier search through the list.
The "plus" and "pencil" action buttons open essentially the same sub-dialog, containing the Name text field and a Color picker:
Restriction: As a general rule, built-in Pathway States cannot be deleted, while the user-added Pathway States can only be added, deleted, and edited by Admins, as Pathway States are installation-wide objects.