Select Virtual Tours -> Editor UI, from side menu.
Here you can see all the elements currently visible in your tour and modify them.
Click on any of UI elements to edit them; you can enable/disable their visibility and change their appearance.
On top of the edit menu you can select to modify environmental elements like:
Font, Change the general font of the whole tour
Main Form, Set the parameters of the general form
Default Markers Style, Set the style parameters of the new Markers
Default POIs Style, Set the style parameters of the new POIs
Presets, Save and load UI presets
Tooltips, View or not the tooltips of the elements when hovering them
After changing the UI click Save in top right corner of the page.