How to Set Line Color in Matplotlib: Simple Guide

To set the line color in Matplotlib, use the color parameter inside the plot() function. You can specify colors by name, hex code, or shorthand letters like 'r' for red.

Syntax

The basic syntax to set line color in Matplotlib is using the color parameter inside the plot() function.

• color: Defines the line color. It accepts color names (e.g., 'blue'), hex codes (e.g., '#FF5733'), or single-letter shortcuts (e.g., 'g' for green).

python

plt.plot(x, y, color='color_value')

Example

This example shows how to plot a simple line graph with a red line using the color parameter.

python

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]
y = [2, 3, 5, 7, 11]

plt.plot(x, y, color='red')
plt.title('Line plot with red color')
plt.xlabel('X axis')
plt.ylabel('Y axis')
plt.show()

Output

A line plot with points connected by a red line.

Common Pitfalls

Common mistakes when setting line color include:

• Using an invalid color name or code, which causes an error.
• Confusing the color parameter with c or facecolor which are used in other plot types.
• Not specifying the color parameter inside the plot() call.

Here is an example showing a wrong and right way:

python

import matplotlib.pyplot as plt

x = [1, 2, 3]
y = [4, 5, 6]

# Wrong: invalid color name
# plt.plot(x, y, color='redd')  # This will cause an error

# Right: valid color name
plt.plot(x, y, color='red')
plt.show()

Output

A line plot with a red line connecting points (1,4), (2,5), (3,6).

Quick Reference

Color Parameter Value	Description	Example
'red'	Named color	color='red'
'r'	Single letter shortcut	color='r'
'#00FF00'	Hex color code	color='#00FF00'
'blue'	Named color	color='blue'
'g'	Single letter shortcut	color='g'

Key Takeaways

Use the color parameter inside plt.plot() to set line color.

Colors can be named strings, hex codes, or single-letter shortcuts.

Invalid color names cause errors, so use valid color values.

The color parameter must be inside the plot() call to work.

Common shortcuts include 'r' for red, 'g' for green, and 'b' for blue.