In the Settings dialogue, the current style for roundabouts is bolded. When you select an existing style, the buttons on the right-hand side are available.
To modify the style for an existing roundabout, select a roundabout, then click the Modify panelRoundabout Properties drop-downRoundabout Styles.
To set the default styles for roundabouts, click the Home tabCreate Design panelJunctions drop-downConfigure Roundabout Tools.
Use Set Current to change a non-current style to the current style.
Use Rename to rename an existing style.
Use New to create a new style based upon the default object style. A new style will be created and added to the list.
Use Edit to edit a selected style in the Drawing Style dialogue.
Use Duplicate to make a copy of a selected style. An efficient way to create a new style based on an existing style is to duplicate the style, and then edit the duplicate.
Use Delete to remove a style from the list. You cannot delete locked styles or Autodesk styles.