textfont color ignored in Sankey diagram

When specifying textfont in a Sankey diagram like this: textfont=dict(color="blue", size=50) the color is ignored, while size works correctly.

A MWE with two figures. The first one has black nodes and (tiny) text, which is correct.

fig_black = go.Figure(data=[
    go.Sankey(
        node=dict(
            pad=15,
            thickness=20,
            line=dict(color="black", width=0.5),
            label=["A1", "A2", "B1", "B2", "C1", "C2"],
            color="black"
        ),
        link=dict(
            source=[0, 1, 0, 2, 3, 3],  # indices correspond to labels, eg A1, A2, A2, B1, ...
            target=[2, 3, 3, 4, 4, 5],
            value=[8, 4, 2, 8, 4, 2]
        ),
        textfont=dict(color="black", size=10)
    ),
])
fig_black.update_layout(title_text="Black")
fig_black.show()

The second one has blue nodes, which is correct, but the text is black when it should be blue.

fig_blue = go.Figure(data=[
    go.Sankey(
        node=dict(
            pad=15,
            thickness=20,
            line=dict(color="blue", width=0.5),
            label=["A1", "A2", "B1", "B2", "C1", "C2"],
            color="blue"
        ),
        link=dict(
            source=[0, 1, 0, 2, 3, 3],  # indices correspond to labels, eg A1, A2, A2, B1, ...
            target=[2, 3, 3, 4, 4, 5],
            value=[8, 4, 2, 8, 4, 2]
        ),
        textfont=dict(color="blue", size=50)
    ),
])
fig_blue.update_layout(title_text="Blue")
fig_blue.show()

I'm using plotly version 4.9.0.

Is the color specification above wrong or is this a bug?

Reproduisez le MWE Sankey fourni en deux figures avec Plotly 4.9.0 et comparez la taille de texte qui fonctionne avec la couleur de texte ignorée. Suivez le traitement de textfont de Sankey, puis ajoutez une couverture montrant que la couleur demandée est rendue ; l’issue ne nomme aucun fichier source ni test pour commencer.