You can override some layer properties displayed in a layout viewport.
Using layer property overrides is an efficient way to display objects with different property settings for color, linetype, lineweight, transparency, and plot style.
For example, if you want objects on the Electrical layer to display prominently in one of two layout viewports, you set a different color override on the Electrical layer for each of the two layout viewports. You can set the color to red for one layout viewport and gray for the other.