How to get the color of the most recent plotted line in Python?

When working with matplotlib plots, you often need to retrieve the color of the most recently plotted line for further customization or analysis. Python provides the get_color() method to access line properties.

Basic Example

Here's how to get the color of the most recent plotted line ?

import numpy as np
import matplotlib.pyplot as plt

# Set figure properties
plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

# Create data points
x = np.linspace(1, 10, 1000)
y = np.linspace(10, 20, 1000)

# Plot line and capture the line object
line, = plt.plot(x, y, c="red", lw=2)

# Get and print the color
print("Color of the most recent plot line:", line.get_color())
plt.show()

Color of the most recent plot line: red

Getting Color from Multiple Lines

When you have multiple lines, you can access the color of the most recent one ?

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 10, 100)

# Plot multiple lines
line1, = plt.plot(x, np.sin(x), label='sin(x)')
line2, = plt.plot(x, np.cos(x), label='cos(x)')
line3, = plt.plot(x, np.tan(x), c='green', label='tan(x)')

# Get color of the most recent line (line3)
print("Most recent line color:", line3.get_color())

# You can also get colors of all lines
print("Line 1 color:", line1.get_color())
print("Line 2 color:", line2.get_color())

plt.legend()
plt.ylim(-2, 2)
plt.show()

Most recent line color: green
Line 1 color: C0
Line 2 color: C1

Using gca() to Get the Latest Line

You can also retrieve the most recent line using gca().get_lines() ?

import numpy as np
import matplotlib.pyplot as plt

x = np.linspace(0, 5, 50)

plt.plot(x, x**2, 'b-', label='x²')
plt.plot(x, x**3, 'r--', label='x³')

# Get the most recent line using gca()
most_recent_line = plt.gca().get_lines()[-1]
print("Most recent line color:", most_recent_line.get_color())
print("Most recent line style:", most_recent_line.get_linestyle())

plt.legend()
plt.show()

Most recent line color: red
Most recent line style: --

Conclusion

Use the get_color() method on line objects to retrieve color information. For the most recent line, either capture the line object directly or use plt.gca().get_lines()[-1] to access it programmatically.