Using theme option boxes you can use 3 different styles, primary, secondary and extra.
But with custom CSS, you can always change any of these menu styles afterwards on a specific extra menu, as they each have their own ID, so we can use any of the styling rule and Add the specific ID at the appropriate place to change it.
When you have one in place you want to change give us a link with specifics and what you want to change and we can precise the rules