Dynamic resource editor for X11 Toolkit applications
Editres is a tool that allows users and application developers to view the full widget hierarchy of any X Toolkit application that speaks the Editres protocol. In addition, editres will help the user construct resource specifications, allow the user to apply the resource to the application and view the results dynamically. Once the user is happy with a resource specification editres will append the resource string to the user's X Resources file.
To install editres, paste this in macOS terminal after installing MacPorts
sudo port install editres