How to invert color of seaborn heatmap colorbar

user_5832773 0
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I use an heatmap to visualize a confusion matrix. I like the standard colors, but I would like to have 0s in light orange and highest values in dark purple.

I managed to do so only with another set of colors (light to dark violet), setting:

colormap = sns.cubehelix_palette(as_cmap=True)
ax = sns.heatmap(cm_prob, annot=False, fmt=".3f", xticklabels=print_categories, yticklabels=print_categories, vmin=-0.05, cmap=colormap)

But I want to keep these standard ones. This is my code and the image I get.

ax = sns.heatmap(cm_prob, annot=False, fmt=".3f", xticklabels=print_categories, yticklabels=print_categories, vmin=-0.05)

enter image description here

seaborn heatmap colors
5 Answers

The default cmap is sns.cm.rocket. To reverse it set cmap to sns.cm.rocket_r

Using your code:

cmap = sns.cm.rocket_r

ax = sns.heatmap(cm_prob,
                 annot=False,
                 fmt=".3f",
                 xticklabels=print_categories,
                 yticklabels=print_categories,
                 vmin=-0.05,
                 cmap = cmap)
user_66176000

To expand on Ben's answer, you can do this with most if not any color map.

import matplotlib.pyplot as plt
import numpy as np
import seaborn as sns
X = np.random.random((4, 4))
sns.heatmap(X,cmap="Blues")
plt.show()
sns.heatmap(X,cmap="Blues_r")
plt.show()
sns.heatmap(X,cmap="YlGnBu")
plt.show()
sns.heatmap(X,cmap="YlGnBu_r")
plt.show()

enter image description here

user_21718570

Did you try to invert the colormap? 

sns.cubehelix_palette(as_cmap=True, reverse=True)
user_41243170
  • only add cmap="rocket_r" to sns.heatmap
    • cmap="rocket": is the default palette of heatmap
    • add_r: to reverse the colors of palette
ax = sns.heatmap(cm_prob, annot=False, fmt=".3f", xticklabels=print_categories, yticklabels=print_categories, vmin=-0.05,cmap="rocket_r")
user_146789740

we can now quickly achieve reverse color just by putting _r in the end.

For example: for viridis => viridis_r

sns.heatmap(corr_matrix, annot=True, cmap='viridis_r');
user_7516890
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