Use the HeaderStyle property to control the appearance of the header row in a GridView control. This property is read-only; however, you can set the properties of the TableItemStyle object it returns. The properties can be set declaratively using one of the following methods:
Place an attribute in the opening tag of the GridView control in the form Property-Subproperty, where Subproperty is a property of the TableItemStyle object (for example, HeaderStyle-ForeColor).
Nest a <HeaderStyle> element between the opening and closing tags of the GridView control.
The properties can also be set programmatically in the form Property.Subproperty (for example, HeaderStyle.ForeColor). Common settings usually include a custom background color, foreground color, and font properties.