You will not be able to set the menu styles if the menu parameters have never been set. After the menu parameters have been set, you may select a menu you want to style as shown below:
You may then change your font, size, color, weight, drop shadow, etc. as shown below. Note that the browser default of underlining links will be overridden here by default. If you want your menu to have an underline, you will need to check the Underline checkbox.
Text color, background colors, and borders and colors for mouse out (link), mouse over (hover) and mouse click (active) events are set in the bottom section of the tool as shown above. You may turn off background color or borders by blanking out the corresponding fields. (It is not necessary to type "-not set-" or "-1".) Block border refers to a border existing around the entire menu and item border refers to a border around each menu item. You may also specify which side(s) you want the border on. By default, all sides are selected. Click Update to save your changes.