To access list of materials used in the design, in order to CHANGE the properties of one of the materials, follow these steps:
Navigate to Global Preferences and Settings and select Materials.
To access the materials added from the design catalogue, open the Materials Imported from Catalogue dropdown menu.
To access the materials created by the user, open the User Created Materials dropdown menu.
Select 'Change' against that desired material.
To access list of materials used in the design, in order to APPLY the one of the materials onto an element, follow these steps:
Select the element on which you want to apply the material, and navigate to the Materials section in the properties panel
Open the material drop down menu.
To access the materials added from the design catalogue, select the Store Materials tab.
To access the materials created by the user, select the User Created tab.
Click on the material thumbnail to apply it on the element.