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?
@nicolaskruchten @wbrgss I'm seeing the same thing with Dash Design Kit
Here is a graph with a theme applied that looks OK

Here is the Sankey:

For good measure I tried forcibly setting the textfont_color like this:
fig = fig.update_traces(textfont_color=theme["text"], selector=dict(type='sankey'))
But as reported by @ttusar it seems to have no effect.
Hi. Issue is still present. Cannot change the color of the text of the Sankey node labels.
Streamlit version: 1.42.2