If the Controls collection has a Count greater than zero, the HasChildren property will return true. Accessing the HasChildren property does not force the creation of a Control.ControlCollection if the control has no children, so referencing this property can provide a performance benefit when walking a tree of controls.
The following code example sets the BackColor and ForeColor of the controls to the default system colors. The code recursively calls itself if the control has any child controls. This code example requires that you have a Form with at least one child control; however, a child container control, like a Panel or GroupBox, with its own child control(s) would better demonstrate the recursion.