You can design feature layout style (FLS) with the following procedure.
Load the genomic sequence of interest into the current feature map.
Default FLS or FLS set in the array is automatically applied to the loaded genome sequence.
Edit the FLS set in this initial state and design a new feature layout style.
Select Settings -> Layout Style ... from the menu.
The "Layout Style" design dialog is displayed.
The state of the lane displayed in this dialog is the currently applied feature layout style.
The style has a name, it is selected in the Feature Layout Style pulldown menu at the top.
If you select a different style from this menu, the layout design of that style will be displayed.
Just displaying it in this dialog will not apply to the Karen feature map.
Click "Apply" to apply that style.