# Rainbow

Canonical URL: https://colorcurio.us/colormaps/tol.rainbow
Source type: Colormap
Type: sequential
Collection: tol
Attribution: Paul Tol, "Colour Schemes" (SRON/EPS/TN/09-002)
License: BSD-3-Clause
Source: https://sronpersonalpages.nl/~pault/
Tags: multi-hue, rainbow-alt, cvd-friendly
Stops: 256

## Summary

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

Tol's continuous 'discrete rainbow' anchor sequence (rainbow_linear) — multi-hue smooth rainbow.

## Perceptual profile (OKLCh)

- Lightness: 0.945 → 0.305 (range 0.639, min 0.305, max 0.945); non-monotonic; midpoint 0.695
- Chroma: min 0.021, max 0.216, mean 0.118
- Hue: 274.0° → 29.9° (span 292.9°), path monotonic-ccw; quadrants: violet, magenta, blue, azure, cyan, mint, green, chartreuse, yellow, orange, red
- Endpoint temperature: cool → warm
- Perceptual ΔE: total 230.3, mean/step 0.903, max step 1.068, smoothness 0.965, speed 0.903

## Colorblind safety (ΔE under simulated CVD)

- Protanopia: ΔE total 172.0; preserves order: no
- Deuteranopia: ΔE total 166.2; preserves order: no
- Tritanopia: ΔE total 226.2; preserves order: no

## Related

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