# Gem

Canonical URL: https://colorcurio.us/colormaps/cmasher.gem
Source type: Colormap
Type: sequential
Collection: cmasher
Attribution: Ellert van der Velden — CMasher (10.21105/joss.02004)
License: BSD-3
Source: https://raw.githubusercontent.com/1313e/CMasher/master/src/cmasher/colormaps/gem/gem_norm.txt
Tags: perceptually-uniform, sequential
Stops: 256

## Summary

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

Multi-hue jewel-toned sequential.

## Perceptual profile (OKLCh)

- Lightness: 0.239 → 0.855 (range 0.617, min 0.239, max 0.855); monotonic; midpoint 0.568
- Chroma: min 0.093, max 0.222, mean 0.164
- Hue: 24.8° → 197.5° (span 187.3°), path monotonic-ccw; quadrants: red, rose, magenta, violet, blue, azure, cyan
- Endpoint temperature: warm → cool
- Perceptual ΔE: total 112.9, mean/step 0.443, max step 0.519, smoothness 0.850, speed 0.443

## Colorblind safety (ΔE under simulated CVD)

- Protanopia: ΔE total 96.7; preserves order: yes
- Deuteranopia: ΔE total 89.8; preserves order: yes
- Tritanopia: ΔE total 104.9; preserves order: yes

## Related

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