You can customize the appearance of the CalendarView and DateEdit controls by setting the themes. The Themes functionality can be added to both the controls using C1ThemeController. Here, we have used a ComboBox control to populate the available themes from the ThemeController. You can use any preferred control to populate themes.

The image below shows the CalendarView control with Office2016DarkGray theme:

The image below shows the DateEdit control with Office2016DarkGray theme:

Refer the code snippet below to observe how ComboBox has been used to populate themes using C1ThemeController:

private void Form_Load(object sender, EventArgs e)
   {
        comboBox.Items.AddRange(C1ThemeController.GetThemes());
   }
private void comboBox_SelectedValueChanged(object sender, EventArgs e)
   {
        c1ThemeController.Theme = comboBox.SelectedItem.ToString();
   }