On a layout, double-click inside a layout viewport to make it the current viewport.
Click Home tab Layers panel Layer Properties. Find
In the Layer Properties Manager, specify the properties to override in the current layout viewport by changing the properties in the following columns:
VP Freeze
VP Color
VP Linetype
VP Lineweight
VP Transparency
VP Plot Style
Any objects with properties set to ByLayer will use the layer properties for that layout viewport instead of the global layer properties. Every layout viewport can have its own set of layer overrides.