Layout with Python - Plotly
https://plotly.com/python/reference/layoutCode: fig.update_layout(hoverlabel_grouptitlefont_color=<VALUE>) Type: color ; family Code: fig.update_layout(hoverlabel_grouptitlefont_family=<VALUE>) Type: string . HTML font family - the typeface that will be applied by the web browser. The web browser will only be able to apply a font if it is available on the system which it operates.