Once the Sorting of a particular field has been determined, a control level text is created that appears above the fields in your list in layout mode.
This control level text is highlighted in purple ('lilac'). You cannot change this.
If you select a sort field, as in the example above, and want if to appear as the control level text, if makes sense to delete the field from the actual body of the list If you do not want the sort field to be elevated to the control level text, delete the control level text using the trash can icon. To delete the control level text, click on the sort field in the Sort fields toolbox and deselect the option Control level text in the lower left window on your screen. This checkbox is selected in the standard.
Click on control level texts to edit them. The whole line (minus the sort field display length) can be filled with text.
Texts for subtotals and counting fields can be edited in the same manner.