# PuBu

Canonical URL: https://colorcurio.us/colormaps/colorbrewer.PuBu
Source type: Colormap
Type: sequential
Collection: colorbrewer
Attribution: Cynthia Brewer & Mark Harrower, ColorBrewer 2.0
License: Apache-2.0
Source: https://colorbrewer2.org/
Tags: sequential, colorbrewer, purple-blue, light-start
Stops: 256

## Summary

PuBu is a sequential colormap from the colorbrewer collection. Inspect its perceptual lightness, chroma, and hue profile on colorcurio.us.

ColorBrewer 2.0 sequential multi-hue 'PuBu' (9-class anchors).

## Perceptual profile (OKLCh)

- Lightness: 0.983 → 0.327 (range 0.657, min 0.327, max 0.983); monotonic; midpoint 0.713
- Chroma: min 0.010, max 0.130, mean 0.070
- Hue: 345.4° → 242.3° (span 109.3°), path monotonic-ccw; quadrants: violet, blue, azure
- Endpoint temperature: warm → cool
- Perceptual ΔE: total 73.2, mean/step 0.287, max step 0.392, smoothness 0.740, speed 0.287

## Colorblind safety (ΔE under simulated CVD)

- Protanopia: ΔE total 65.4; preserves order: yes
- Deuteranopia: ΔE total 69.2; preserves order: yes
- Tritanopia: ΔE total 75.4; preserves order: yes

## Related

- Family: https://colorcurio.us/colormaps/families/colorbrewer
- All colormaps: https://colorcurio.us/colormaps