Here is a simple example of line plot without specifying colors using the Matplotlib library.

import matplotlib.pyplot as plt
import pandas as pd

# We create our dataframe
df = pd.DataFrame(index=range(0,10), data={"col1" : range(0,10)})

fig, axes = plt.subplots(1,1, figsize=(8,6))

# We do a line plot on the axes
axes.plot(df.index, df["col1"])

# Fixing the layout to fit the size
fig.tight_layout()

# Showing the plot
plt.show()

Simple plotting example using Matplotlib

Changing the line color

We can specify colors for each dataset that we plot with the c=color parameter. (e.g. c='red')

import matplotlib.pyplot as plt
import pandas as pd

# We create our dataframe
df = pd.DataFrame(index=range(0,10), data={"col1" : range(0,10)})

fig, axes = plt.subplots(1,1, figsize=(8,6))

# We do a line plot on the axes
axes.plot(df.index, df["col1"], c='red')

# Fixing the layout to fit the size
fig.tight_layout()

# Showing the plot
plt.show()

Plotting a red line

Changing the theme

Matplotlib comes with different themes that you can chose from

import matplotlib.pyplot as plt

# Print out the available styles
print(plt.style.available)

Check what style is available

Here is a practical example of changing the matplotlib theme.

import matplotlib.pyplot as plt
import pandas as pd

# Changing the matplotlib style theme
plt.style.use('ggplot')

# We create our dataframe
df = pd.DataFrame(index=range(0,10), data={"col1" : range(0,10)})

fig, axes = plt.subplots(1,1, figsize=(8,6))

# We do a line plot on the axes
axes.plot(df.index, df["col1"], c='red')

# Fixing the layout to fit the size
fig.tight_layout()

# Showing the plot
plt.show()

Changing the theme and plotting a red line

As you can see we just changed the theme of our plot.

Here you are ! You now know how to change both the color of your plot and its theme.