# Turbo

Canonical URL: https://colorcurio.us/colormaps/d3.turbo
Source type: Colormap
Type: sequential
Collection: d3
Attribution: Mikhailov 2019 — "Turbo, an Improved Rainbow Colormap for Visualization" (Google AI Blog)
License: Apache-2.0 (Google) / ISC (d3 port)
Source: https://github.com/d3/d3-scale-chromatic/blob/main/src/sequential-multi/turbo.js
Tags: rainbow, dark-bg, perceptually-uniform
Stops: 256

## Summary

Turbo is a sequential colormap from the d3 collection. Inspect its perceptual lightness, chroma, and hue profile on colorcurio.us.

Improved rainbow that reads on dark backgrounds.

## Perceptual profile (OKLCh)

- Lightness: 0.222 → 0.416 (range 0.670, min 0.222, max 0.892); non-monotonic; midpoint 0.892
- Chroma: min 0.019, max 0.229, mean 0.178
- Hue: 356.3° → 30.7° (span 325.8°), path monotonic-ccw; quadrants: magenta, violet, blue, azure, cyan, mint, green, chartreuse, yellow, orange
- Endpoint temperature: warm → warm
- Perceptual ΔE: total 233.6, mean/step 0.916, max step 5.722, smoothness 0.379, speed 0.916

## Colorblind safety (ΔE under simulated CVD)

- Protanopia: ΔE total 186.8; preserves order: no
- Deuteranopia: ΔE total 170.6; preserves order: no
- Tritanopia: ΔE total 191.1; preserves order: no

## Related

- Family: https://colorcurio.us/colormaps/families/d3
- All colormaps: https://colorcurio.us/colormaps