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How to Change the Color of a Bar Graph in Python?

Published in Bar Graph Colors 3 mins read

You can change the color of a bar graph in Python using the color argument when creating the bar plot.

Changing Bar Color

Here's how you can modify the color of bars in a bar graph using the color argument, often within libraries like Matplotlib:

  • Using a Single Color: To set all bars to the same color, provide a color name (e.g., 'red', 'blue', 'green') or a hexadecimal color code (e.g., '#FF0000' for red) to the color argument.

    import matplotlib.pyplot as plt

# Sample data
categories = ['A', 'B', 'C', 'D']
values = [25, 40, 30, 55]

# Create the bar plot with a specified color
plt.bar(categories, values, color='green')
plt.xlabel('Categories')
plt.ylabel('Values')
plt.title('Bar Graph with Green Bars')
plt.show()

  • Using Different Colors for Each Bar: To assign different colors to individual bars, provide a list of color names or hex codes to the color argument. The length of the list must match the number of bars.

    import matplotlib.pyplot as plt

# Sample data
categories = ['A', 'B', 'C', 'D']
values = [25, 40, 30, 55]
colors = ['red', 'blue', 'green', 'purple']  # Different colors for each bar

# Create the bar plot with different colors
plt.bar(categories, values, color=colors)
plt.xlabel('Categories')
plt.ylabel('Values')
plt.title('Bar Graph with Varied Colors')
plt.show()

  • Using RGB Values: You can also specify colors using RGB (Red, Green, Blue) values. These values typically range from 0 to 1, representing the intensity of each color component. You can also include an alpha value for transparency. The reference mentions that RGB is a way of creating colors, requiring red, green, blue, and transparency values.

    import matplotlib.pyplot as plt

# Sample data
categories = ['A', 'B', 'C', 'D']
values = [25, 40, 30, 55]
rgb_colors = [(0.1, 0.2, 0.5, 0.6), (0.1, 0.3, 0.5, 0.6), (0.1, 0.4, 0.5, 0.6), (0.1, 0.5, 0.5, 0.6)] #RGBA values

# Create the bar plot with RGB colors
plt.bar(categories, values, color=rgb_colors)
plt.xlabel('Categories')
plt.ylabel('Values')
plt.title('Bar Graph with RGB Colors')
plt.show()

Color Customization Options

Here's a table summarizing different ways to specify bar colors:

Method Description Example
Color Name Use a predefined color name. color='red'
Hex Code Use a hexadecimal color code. color='#FF0000'
RGB Tuple Use an RGB tuple (Red, Green, Blue), with values between 0 and 1. color=(0.2, 0.4, 0.6)
RGBA Tuple Use an RGBA tuple (Red, Green, Blue, Alpha), with values between 0 and 1. color=(0.2, 0.4, 0.6, 0.8)
Color List Use a list of color names, hex codes, RGB tuples, or RGBA tuples, one per bar. color=['red', 'blue', 'green', 'yellow']

By utilizing the color argument and the various color specification methods, you can effectively customize the appearance of your bar graphs in Python.

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