Plotly: Change transparency of fillcolor

Question

I'm trying to change the default color of a fillcolor in Plotly to another transparent one, but when I change the fillcolor it is not transparent anymore.

trace = (go.Scatter(x=[30,45],y=[3000,3000],
                fill='tozeroy', 
#                     fillcolor='green',
#                     fillcolor='rgb(26,150,65,0.5)',
#                     fillcolor=dict(color='rgb(26,150,65,0.5)'),
#              fillcolor=dict(marker=dict(color='rgb(26,150,65,0.5)')),
                opacity=0.1,
                showlegend=False,
                hoverinfo='none',
                mode='none'))
py.offline.iplot(go.Figure(data=[trace]))

This default call results in the following:

and when I use fillcolor='green' it results in this nontransparent color:

The commented code results in the default case again.

Solution 1

You would need to use rgba to specify the alpha channel as well, rgb ignores the transparency.

import plotly
trace = plotly.graph_objs.Scatter(x=[30,45],y=[3000,3000],
                                  fill='tozeroy', 
                                  fillcolor='rgba(26,150,65,0.5)',
                                  mode='none')
plotly.offline.iplot(plotly.graph_objs.Figure(data=[trace]))

Solution 2

Looks like there is for traces. opacity=0.5 is an argument. https://plotly.com/python/marker-style/

Comments

[Jacquot]

I cannot propose an edit directly, but it would be a great addition if the title was made more explicit, like : "Plotly scatter plot: Change transparency of fillcolor for filled area"

[Hans Bambel]

I don't think this is explicit to the Scatter plot, or is it? Also a fillcolor is inherently filling an area, right?

[Jacquot]

No, it isn't. And yes. My comment came from the frustration of searching some time for that post, and adding specific keywords can make for a better search engine indexation.

[mzoll]

is there no option to do this by some plot-native key like 'opacity=0.3' or something, rather than to manipulate the color object/directive

[Quint]

@mzoll Looks like there is for traces opacity=0.5 is an argument. plotly.com/python/marker-style