1. Overview
Motion on screen can make people ill. Parallax, zooming transitions and bouncing animations can cause dizziness and nausea for people with vestibular disorders. Low contrast and colour-only meaning shut out people with low vision or colour blindness. Speech without captions shuts out deaf people.
iOS lets people fix these problems once, in Settings, for every app. Some settings work without any help from your app. Many only send your app a signal. If your app ignores the signal, the setting does nothing in your app. EN 301 549 clause 11.7 requires apps to follow these preference settings.
This lesson covers the motion, contrast and colour settings, and how to read each one in code. It then covers captions and audio description for video.
Unlock the rest of this lesson
You have read the free preview of Motion, contrast, colour and media settings in Module 5: iOS accessibility. The full lesson, its knowledge check and the module certificate come with a plan, bought here on the web.
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Free with no account: the first lesson, Why accessibility, and who it is for, the European Accessibility Act flashcards and the overview of every lesson.
Sources
- Apple Developer, SwiftUI environment values: accessibilityReduceMotion, colorSchemeContrast, accessibilityDifferentiateWithoutColor, accessibilityReduceTransparency, accessibilityPlayAnimatedImages and accessibilityDimFlashingLights. accessibilityIgnoresInvertColors(_:).
- Apple Developer, UIKit: isReduceMotionEnabled, isDarkerSystemColorsEnabled, shouldDifferentiateWithoutColor and accessibilityContrast.
- Apple Developer, AVFoundation: appliesMediaSelectionCriteriaAutomatically, describesMusicAndSoundForAccessibility and describesVideoForAccessibility.
- Apple, Human Interface Guidelines: Accessibility, for contrast, system colours and audio cues. iPhone User Guide: Customize onscreen motion and Change display colors.
- ETSI, CEN and CENELEC, EN 301 549 V4.1.1 (2026-09), clauses 11.1.2.2, 11.1.2.5, 11.1.4.1, 11.1.4.3, 11.1.4.11, 11.2.2.2, 11.2.3.1 and 11.7, available from the ETSI standards server.
- W3C, Web Content Accessibility Guidelines (WCAG) 2.2, with Understanding 1.4.1 Use of Color and Understanding 2.2.2 Pause, Stop, Hide, and the Group Note Guidance on Applying WCAG 2 to Non-Web Information and Communications Technologies (WCAG2ICT).
