For example, if the AssignedValues property contains cvColor, and cvTitleCaption, then the column's font and title caption have been changed and no longer track with changes made to their default source. 

Many column properties obtain their values from external sources, such as properties of the associated TField objects. The column will reflect changes made to the property's default source until a value is assigned to the column property. After assignment, the column property is independent of its default source. 

Title 

TColumnTitle 

RestoreDefaults 

Restoring Default Values to a Column