ExcelFile.GetTheme Method
This is an advanced method, that allows you to get the full theme in use. Normally you will just want to replace colors, and you can do this with SetColorTheme(TPrimaryThemeColor, TDrawingColor) and GetColorTheme(TPrimaryThemeColor) methods. Much of the functionality in a theme applies to PowerPoint, not Excel.
Syntax
Namespace: FlexCel.Core
public abstract TTheme GetTheme()