ChooseColor()

         Allows color choice

    Syntax:

         ChooseColor( [nRow], [nCol], [lShowColor] ) -> Nil

         nRow       : Row of window, by default 3.
         nCol       : Column of window, by default 28.
         lShowColor : A logic value indicating if the color in string
                      format must be showed during selection. By default
                      is false, .F.

    Description:

         Allows to user to choose a color.

    Return:

         The color in string format or Nil if Esc has been pressed.

    Example:

         ? "Selected Color is " + ChooseColor( 3, 28, .T. )