Why did the colors need to change?
The legacy colors did not meet the Web Content Accessibility Guidelines for color contrast.
Why are these accessibility guidelines important?
Signal's goal is to make private communication as widely available as possible. An estimated 253 million people live with visual impairment. By improving color contrast throughout Signal to meet WCAG level AA (with a 4.5:1 color contrast ratio), the palette compensates for vision loss equivalent to approximately 20/40 vision. This dramatically increases the number of people who are able to use Signal as the community continues to grow.
Why were the current set of colors chosen?
There are now 12 core colors in Signal. The core colors also have 24 corresponding tints and shades that are used for highlights and in interface elements like quoted replies. Signal also includes a full-spectrum gray palette of 22 colors (including black and white) that are used throughout the UI on text and backgrounds.
This means that there are 58 different colors in Signal that were designed to work seamlessly across both the Light and Dark themes while adhering to the target 4.5:1 color contrast ratio. Our goal was to design a palette that is unique to Signal while maintaining flexibility to incorporate additional colors as we add new features to the application.
Where can I find additional information?
You can learn how to change your conversation colors or theme here.