Learn how to apply a single material to all objects within Blender and temporarily replace any applied materials. Details below...
Patreon: / michaelbullo
Render Properties - Render Engine - Cycles
3D Viewport - Viewport Shading - Rendered
View Layer Properties - Override - Material Override
Setting a material for Material Override will see this material applied to all content...
- within the 3D Viewport
- that is rendered out of Blender