I am creating a simple line chart with plotly express. There are 3 lines and I would like to assign custom colors to each line. Is this possible?
Something like:
fig = px.line(df, 'x', 'y')
fig.update_traces(line_color='#456987')
fig2 = px.line(df, 'xx', 'yy')
fig2.update_traces(line_color='#147852')
from what I understood, you can use all the plotly properties with plotly.express by passing the arguments in the update_traces method.
Cheers
Matteo
Can someone extend this answer and cater for the case of multiple lines in the same plot? For example, say the figure is created by:
fig = px.line(df, x="Date", y=["Averaged", "Raw"])
How can I control the colors assigned to the lines? I tried fig.update_traces(line_color=["#456987", "#147852"]) but it didn’t work… Any idea?
This worked well for me:
fig = px.line(df, x=“day”, y=“count”, color=‘year’, color_discrete_sequence=[‘gray’, ‘blue’])
You can add a color list using the color_discrete_sequence.
2 Likes
@drorata try this:
import plotly.express as px
import pandas as pd
df = pd.DataFrame(dict(
Date=[1,2,3],
Averaged=[1,2,3],
Raw=[2,3,1]
))
fig = px.line(df, x="Date", y=["Averaged", "Raw"],
color_discrete_map={
"Average": "#456987",
"Raw": "#147852"
})
fig.show()
1 Like
@nicolaskruchten That’s the right direction I believe, but I’m afraid it is not doing what I’m expecting. For example, the following:
fig = px.line(df, x="Date", y=["Averaged", "Raw"],
color_discrete_map={
"Average": "blue",
"Raw": "goldenrod"
})
fig.show()
yields something like:
As you can see, the color of “Averaged” is not really blue… What’s the solution?
The values must match exactly so you need the “d” in “Averaged” 
(The error comes from my code, clearly, so the fault is mine!)