property Schedule.UseVisualTheme as UIVisualThemeEnum
Specifies whether the control uses the current visual theme to display certain UI parts.

UIVisualThemeEnum An UIVisualThemeEnum expression that specifies which UI parts of the control are shown using the current visual theme.
By default, the UseVisualTheme property is exDefaultVisualTheme, which means that all known UI parts are shown as in the current theme. The UseVisualTheme property may specify the UI parts that you need to enable or disable the current visual theme. The The UseVisualTheme property has effect only a current theme is selected for your desktop. The UseVisualTheme property. Use the Appearance property of the control to provide your own visual appearance using the EBN files. The VisualDesign property may be used to change the visual aspect of the entire control at design mode.

The following screen shot shows the control while the UseVisualTheme property is exDefaultVisualTheme:

since the second screen shot shows the same data as the UseVisualTheme property is exNoVisualTheme: