Visibility of objects can be hidden by type.  The Show... commands provide a way to toggle the visibility of icons, walls, floors, text, line dimensions, area dimensions and imports. You can also force wall dimensions to remain visible, even though the default behavior is to only show wall dimensions when adding or selecting them.

Color display for icons and floors are enabled by default.  (This will only be apparent if you have assigned colors for these objects in your plan.) To disable this feature and suppress the display of colors, select Hide Colors from the View menu. To return to the default where colors are displayed, select Show Colors.