Hover color of menu items

On the main menu we have an item ‘Cursussen’ with 7 submenu’s.
When you hover over one of those 7 items it changes color and the color of the previously visited menu turns back to white again. I have now added an extra option ‘English courses’ link but when you hover over that option the previously visited menu item does not turns back to white.
Am I missing a styling option here or is this by design or a bug?

The page I need help with: [log in to see the link]