Color vision deficiency (CVD, color blindness) is the failure or decreased ability to distinguish between colors under normal lighting conditions. There are over 300 million people worldwide with CVD, including approx. 1 in 12 men (8%) and 1 in 250 women (0.5%). CVD can limit a user's ability to interact with websites and software packages that are otherwise basic commodities. User interface designers have taken various approaches to tackle the issue with some interfaces offering a high contrast mode, and others integrating color-blind awareness into their website design process. The Web Content Accessibility Guidelines (WCAG) outline some best practices for maintaining accessibility that have been adopted and recommended by several governments; however, it is currently uncertain how this impacts perceived user functionality and if this could result in a reduced aesthetic look. In our work, we present a subjective user study to measure the loss of functionality and aesthetics as potentially seen by CVD observers for 20 popular websites and software packages. As recruiting participants with CVD is non-trivial, we developed a simulation-based pipeline instead for our full-reference mean opinion score experiment, which as far as we know is a novelty in the field. Our results show that relative aesthetics and functionality correlate positively and that an operating-system-wide high contrast mode can reduce both aesthetics and functionality for CVD users. Finally, we propose a AAA--A classification of the interfaces we analyzed.

翻译：色觉缺陷（CVD，色盲）是指在正常光照条件下无法或难以区分颜色的现象。全球超过3亿人患有色觉缺陷，其中约每12名男性中有1人（8%）、每250名女性中有1人（0.5%）受其影响。色觉缺陷会限制用户与原本属于基本常用品的网站及软件包进行交互的能力。用户界面设计者已采取多种方法解决该问题，部分界面提供高对比度模式，另一些则将色盲友好理念融入网站设计流程。《网页内容无障碍指南》（WCAG）概述了维护可访问性的最佳实践，已被多国政府采纳和推荐；然而，目前尚不明确这种实践对用户感知功能性的影响，以及是否可能导致审美效果下降。本文通过主观用户研究，测量色觉缺陷观察者感知的20个热门网站和软件包的功能性损失与审美损失。由于招募色觉缺陷参与者具有相当难度，我们开发了基于仿真流程的全参考平均意见得分实验方法——据我们所知，这在该领域具有创新性。结果表明，相对审美与功能性呈正相关，操作系统级高对比度模式会同时降低色觉缺陷用户的审美与功能性体验。最后，我们提出对所分析界面的AAA-A等级分类方案。