The signature of this method is the following:

Symbol CreateSymbolFactory(TMLayer layer, Color color, int index);

The index parameter passed to this factory specifies a zero-based index of color in the color ramp. Two special values of indices are also possible: -1 means that a symbol for the mid color of the color ramp is requested (this case is used with the UniqueValueRenderer when classification ranges are missing) and -2 means that out-of-range symbol is requested.

Target Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows Server 2008 family

Reference