Categories
matplotlib pandas python seaborn

Seaborn palettes – prevent recycling of colors

Seaborn allows defining color palettes that contain multiple colors, useful for charts with many lines. However, when setting the palette to one with multiple colors, only the first six are used, after which colors recycle, making it hard to distinguish lines. This can be overridden by explicitly calling the palette, but that’s not convenient. Is there a way to force the Seaborn current palette not to recycle colors, when more than 6 are defined?

Example:

from matplotlib import pyplot as plt
import pandas as pd
import seaborn as sb
# Define a palette with 8 colors
cmap = sb.blend_palette(["firebrick", "palegreen"], 8)
sb.palplot(cmap)

palette with 6 colors

# Set the current palette to this; only 6 colors are used
sb.set_palette(cmap)
sb.palplot(sb.color_palette() )

palette with 6 colors

df = pd.DataFrame({x:[x*10, x*10+5, x*10+10] for x in range(8)})
fig, (ax1, ax2) = plt.subplots(2,1,figsize=(4,6))
# Using the current palette, colors repeat
df.plot(ax=ax1)
ax1.legend(bbox_to_anchor=(1.2, 1))
# using the palette that defined the current palette, colors don't repeat
df.plot(ax=ax2, color=cmap)
ax2.legend(bbox_to_anchor=(1.2, 1)) ;

charts with 6 or 8 colors used