Creating an annotated heatmap with figure factory using a custom color scale (as seen below) leads to a ValueError: "map object not subscriptable." `import plotly.figure_factory as ff` ` ` `data_test2 = ff.create_annotated_heatmap(z=z, x=x, y=y, colorscale=[[0.0, 'rgb(250,0,0)'], [0.5, 'rgb(250,250,250)'], [1.0, 'rgb(0,0,0)']], annotation_text=df_str, showscale=True)` I fixed this by explicitly defining the map objects for `min_col` and `max_col` in `_AnnotatedHeatMap.get_text_color()` as lists.