The iOS design system is designed to be compliant with accessibility standards. Our components are flexible, readable, and adaptable for usage by a wide range of users, providing an optimal and user-friendly experience for everyone, including individuals with special needs due to visual, motor, auditory, speech, or cognitive impairments.

Color Contrast Ratio

To ensure that your users can easily read and make out the text and visual elements in your app, you need to employ sufficient color contrast. Color contrast is the ratio measuring the difference between the color of the foreground element against the color of the background. Achieving the minimum contrast ratio ensures that all text and visual elements in our design system are legible to all users including those who may be visually impaired and/or color-blind. If the color appears faint against the background, it may be a sign that the color has insufficient color contrast. First, determine its current contrast ratio, second, determine the target contrast ratio of the UI element (e.g., 3:1, 4.5:1, 7:1), and lastly, follow our color pairing system. To validate this, use a color contrast calculator.

Color Pairings [Methodology]

The Horizon color palette has been designed to comply with WCAG accessibility standards with a color pairing system that allows you to easily pair color combinations and achieve your desired color contrast.

Color Pairing for 4.5:1 Contrast (Default)

To ensure the minimum color contrast ratio of 4.5:1 for small text (below 18 point regular or 14 point bold) is met, pairing any color that is five steps apart will achieve this. For example, pairing the fourth color with the ninth color ensures that the minimum color contrast for normal text is met. For a minimum color contrast ratio for text and content, we recommend a 4.5:1 color contrast ratio.

Color Pairing for 3:1 Contrast

To ensure a minimum of 3:1 color contrast ratio for large text (18 point and above regular or 14 point and above bold) and decorative elements are met, pairing any color that is four steps apart will achieve this. For example, pairing the fourth color with the eighth color in the spectrum ensures that the minimum color contrast ratio for large text, bold text, graphical objects, and user interface components is met. For graphical elements, we recommend a 3:1 color contrast ratio.

Color Pairing for 7:1 Contrast

To ensure the minimum color contrast ratio of 7:1 is met, pairing any color that is seven steps apart will achieve this. For example, pairing the fourth color with the eleventh color ensures that the minimum color contrast for a high-contrast theme is met.

Increase Contrast Mode

To support iOS accessibility features such as “Increase Contrast”, we have created a color palette that automatically enhances the color contrast of app foreground and background colors when users select “Increase Contrast” in the system accessibility settings.

Dynamic Type

Built-In Text Styles

Applying iOS built-in text styles allows your app to take advantage of accessibility features, such as dynamic type, which provides users the flexibility of choosing their preferred text size. It also automatically adjusts tracking and leading for every font size.

SAP Fiori for iOS uses SAP 72 font, and supports dynamic type to enable accessibility features. Learn more in Typography.

Here are some examples of our components adapting to larger text sizes, and a few tips when designing a custom component.

Rearranging Layouts

Sometimes it is necessary for a component to rearrange its layout in larger text size settings. The image and status of the object header move to the top of the component, allowing text labels below them to have more space to grow.

Stacking Text Labels

Form cells adapt to larger text sizes by vertically stacking the key label and value. In this case, it is crucial to allow text labels to display more content instead of truncating them.

iOS Accessibility Features

In addition to color contrast ratio, the “Increase Contrast” feature, and dynamic type, there are more ways to ensure that your app is accessible to everyone. iOS provides guidance on how to enable accessibility features such as voice-over, reading support, switch control, dictation, and much more. See Accessibility on iOS for more information.

Resources

Related Foundations: Colors, Typography