How to Set Color of Scatter Plot in Matplotlib Easily

To set the color of a scatter plot in Matplotlib, use the c or color parameter inside plt.scatter(). You can pass a single color name, a list of colors, or a colormap to customize the points' colors.

Syntax

The basic syntax to set color in a scatter plot is:

• plt.scatter(x, y, c=color) where color can be a single color string, a list of colors, or numeric values for colormapping.
• plt.scatter(x, y, color=color) also works for a single color.

Here, x and y are data points. The c parameter controls the color of each point.

python

plt.scatter(x, y, c=color)
plt.scatter(x, y, color=color)

Example

This example shows how to set a single color and multiple colors for scatter plot points.

python

import matplotlib.pyplot as plt

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

# Single color for all points
plt.scatter(x, y, color='red')
plt.title('Scatter plot with single color')
plt.show()

# Multiple colors for each point
colors = ['red', 'green', 'blue', 'orange', 'purple']
plt.scatter(x, y, c=colors)
plt.title('Scatter plot with multiple colors')
plt.show()

Output

Two scatter plots displayed: first all points red, second points colored red, green, blue, orange, purple respectively.

Common Pitfalls

Common mistakes when setting scatter plot colors include:

• Using color with a list of colors instead of c. The color parameter expects a single color, while c can accept a list.
• Passing numeric values to c without specifying a colormap, which may cause unexpected colors.
• Using invalid color names or formats.

Correct usage example:

python

import matplotlib.pyplot as plt

x = [1, 2, 3]
y = [3, 2, 1]
colors = ['red', 'green', 'blue']

# Wrong: color expects a single color, not a list
# plt.scatter(x, y, color=colors)  # This will raise an error

# Right: use c for list of colors
plt.scatter(x, y, c=colors)
plt.show()

Output

Scatter plot with points colored red, green, and blue respectively.

Quick Reference

Parameter	Description	Example
c	Color or sequence of colors for points	'red', ['red', 'blue'], numeric array
color	Single color for all points	'green', '#FF00FF'
cmap	Colormap used when c is numeric	'viridis', 'plasma'
alpha	Transparency level (0 to 1)	0.5 for half transparent

Key Takeaways

Use the 'c' parameter to set colors for individual scatter plot points.

Pass a single color string to 'color' for uniform point color.

Provide a list of colors to 'c' to color points differently.

Use numeric values with 'c' and specify 'cmap' for color gradients.

Avoid passing a list to 'color' as it expects a single color.