'return individual highlighting theme elements.
fgBg - string (\'fg\'or\'bg\') or None, if None return a dictionary
containing fg and bg colours (appropriate for passing to Tkinter in,
e.g., a tag_config call), otherwise fg or bg colour only as specified.'

def GetHighlight(self, theme, element, fgBg=None):

    if self.defaultCfg['highlight'].has_section(theme):
        themeDict = self.GetThemeDict('default', theme)
    else:
        themeDict = self.GetThemeDict('user', theme)
    fore = themeDict[(element + '-foreground')]
    if (element == 'cursor'):
        back = themeDict['normal-background']
    else:
        back = themeDict[(element + '-background')]
    highlight = {'foreground': fore, 'background': back}
    if (not fgBg):
        return highlight
    else:
        if (fgBg == 'fg'):
            return highlight['foreground']
        if (fgBg == 'bg'):
            return highlight['background']
        else:
            raise InvalidFgBg, 'Invalid    fgBg    specified'
