message: [line chart] fix time shift color
diff: @@ -946,7 +946,7 @@ class NVD3TimeSeriesViz(NVD3Viz):
  if isinstance(series_title, string_types):
  series_title += title_suffix
  elif title_suffix and isinstance(series_title, (list, tuple)):
  - series_title = series_title + (title_suffix,)
  + series_title = text_type(series_title[-1]) + title_suffix
  values = []
  for ds in df.index:
  