Modify an accent light

Press the L key (or select Appearance > Accent Lights) to open the Accent Lights interface.
In the Accent Lights interface, right-click a light icon and select Properties.
Use the controls in the window that opens to make interactive changes to the accent light. See About the Accent Light Properties window.
Select other accent lights in the scene to view and edit their properties while the Accent Light Properties window is still open.