Color scales that are effective in both color and grayscale

TL;DR

This paper explores the design of color scales that maintain visual effectiveness in both color and grayscale, proposing solutions that maximize chroma while varying hue linearly, suitable for applications requiring grayscale compatibility.

Contribution

It introduces a method to identify color scales with linear hue variation that optimize chroma in both color and grayscale modes, providing practical solutions for color scale design.

Findings

Identifies two classes of color scales with opposite hue directions.

Achieves average chroma levels of 65-77% of pure colors.

Provides scalable solutions for effective color scales in grayscale.

Abstract

We consider the problem of finding a color scale which performs well when converted to a grayscale. We assume that each color is converted to a shade of gray with the same intensity as the color. We also assume that the color scales have a linear variation of intensity and hue, and find scales which maximize the average chroma (or "colorfulness") of the colors. We find two classes of solutions, which traverse the color wheel in opposite directions. The two classes of scales start with hues near cyan and red. The average chroma of the scales are 65-77% those of the pure colors.