52

How can I set the color of a line in plotly?

import plotly.graph_objects as go
from plotly.subplots import make_subplots


fig = make_subplots(rows=2, cols=1, subplot_titles=('Plot 1', 'Plot 2'))

# plot the first line of the first plot
fig.append_trace(go.Scatter(x=self.x_axis_pd, y=self.y_1, mode='lines+markers', name='line#1'), row=1, col=1)  # this line should be #ffe476

I tried fillcolor but that I suspected doesn't work because this is a simple line.

Trenton McKinney
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Vader
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5 Answers5

61

You can add line=dict(color="#ffe476") inside your go.Scatter(...) call. Documentation here: https://plot.ly/python/reference/#scatter-line-color

nicolaskruchten
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42

@nicolaskruchten is of course right, but I'd like to throw in two other options:

line_color="#0000ff"

And:

 fig['data'][0]['line']['color']="#00ff00"

Or:

 fig.data[0].line.color = "#00ff00"

I particularly appreciate the flexibility of the latter option since it easily lets you set a new color for a desired line after you've built a figure using for example fig.append_trace(go.Scatter()) or fig = go.Figure(data=go.Scatter)). Below is an example using all three options.

Code 1:

import plotly.graph_objects as go
import numpy as np

t = np.linspace(0, 10, 100)
y = np.cos(t)
y2= np.sin(t)
fig = go.Figure(data=go.Scatter(x=t, y=y,mode='lines+markers', line_color='#ffe476'))
fig.add_trace(go.Scatter(x=t, y=y2,mode='lines+markers', line=dict(color="#0000ff")))
fig.show()

Plot 1:

enter image description here

Now you can change the colors directly if you insert the snippet below in a new cell and run it.

Code 2:

fig['data'][0]['line']['color']="#00ff00"
fig.show()

Plot 2:

enter image description here

vestland
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4
fig.add_trace(
                go.Scatter(
                    x=list(dict_val['yolo_timecost'].keys()),
                    y=signal.savgol_filter(list(dict_val['yolo_timecost'].values()),2653,3),
                    mode='lines',
                    name='YOLOv3实时耗时',
                    line=dict(
                        color='rgb(204, 204, 204)',
                        width=5
                    ),
                    ),
                )
yu jiang
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    While this code snippet may solve the question, [including an explanation](//meta.stackexchange.com/questions/114762/explaining-entirely-code-based-answers) really helps to improve the quality of your post. Remember that you are answering the question for readers in the future, and those people might not know the reasons for your code suggestion. – Maximouse Apr 18 '20 at 08:37
  • @yujiang I see you are referring to a data sample that does not exist. It would probably be better to provide a complete suggestion. – vestland Dec 02 '21 at 13:23
2
fig.data[0].line.color = 'rgb(204, 20, 204)'
Miladiouss
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2

You can use color_discrete_sequence like that

import plotly.express as px
df = px.data.gapminder().query("country=='Canada'")
fig = px.line(df, x="year", y="lifeExp", title='Life expectancy in Canada',color_discrete_sequence=["#ff97ff"])
fig.show()
Titouan Quintin
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