Contrast vs APCA

This is a slightly deeper discussion on accessibility best practices, where the author argues that the current method of calculating colour contrast for digital accessibility, based on the Web Content Accessibility Guidelines (WCAG), is inadequate. Colour contrast is the contrast between text and its background, which is recommended to be 4:5.1 as per the guidelines. The author proposes the use a new algorithm called APCA, which aims to more accurately predict the perceived contrast of colours by factoring in human visual perception. The article uses a “famous orange button problem” as an example of where the traditional WCAG method fails to accurately represent readability. APCA, while still under development, offers a more comprehensive solution by taking into account factors like colour relationships, text size, and text weight. It provides a “readability score” instead of a traditional contrast ratio, advocating for a minimum “Lc Score” of 60 for accessibility.