[FIXED] Matplotlib dulls the color red in the plot

Issue

When I plot a graph in Spyder using Matplotlib, the color red will be sometimes be dulled. For example,

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0,10,100)
y = 2*x

plt.plot(x,y, color = 'r', linewidth = 10)
plt.show()

will produce the image

instead of

If I restart Spyder after seeing the dulled red color, then it produces the good plot with the normal red color. I've only noticed this when plotting with the color red. The versions I'm using are Python 3.7.0, Spyder 3.3.4, IPython 7.2.0, and Matplotlib 3.0.2. I'm also using a Mac Mojave, if that's relevant.

Solution

Someplace before executing your code you will have a line saying something like

import seaborn as sns
sns.set(style="white")

or similar.

Complete code:

import seaborn as sns
sns.set(style="white")

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0,10,100)
y = 2*x

plt.plot(x,y, color = 'r', linewidth = 10)
plt.show()

The explanation is that seaborn.set updates the colors if its color_codes argument is set to True (which is the default).

color_codes : bool If True and palette is a seaborn palette, remap the shorthand color codes (e.g. "b", "g", "r", etc.) to the colors from this palette.

There is also an example in the seaborn documentation.

So you can use

import seaborn as sns
sns.set(style="white", color_codes=False)

to get

or just not use .set at all.

Answered By - ImportanceOfBeingErnest