Color contrast between text and background is very important for perceivability. As colors come closer to each other, they’re more difficult to distinguish. Notice that colors that work well with big font sizes may not for smaller text.

Three blocks of text, each block with three lorem ipsum paragraphs in three different text sizes. The first block is white over black, color contrast of 21 to 1. Works every time. The second block is a ratio of 4.5 to 1 good for the two larger paragraphs but already not enough for the smallest one. The third block has a ratio of 2.9 to 1. It is a bad ratio even for the largest text size.

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If you want to keep yourself up to date with what’s going on, or what has been published lately, on how to develop more accessible mobile apps, make sure you subscribe to Accessible Mobile Apps Weekly by @RobinKanatzar from @accessible_apps.

@NSSpain has a great history of having amazing accessibility talks in their schedule! “Accessibility in the Real World”, by @Sommer: https://vimeo.com/235317172 “How to build an app for everyone”, by @NovallSwift: https://vimeo.com/362163043 The super fun "Choose your own SwiftUI adventure - 3 Accessibility", by @twostraws and @PinkerStraws: https://vimeo.com/481768105 And, of course, this year's great "Bas: My Accessibility Story", by @basthomas: https://vimeo.com/751176747

Since iOS 14, you can get a human readable localised name for a UIColor, with a very useful property called accessibilityName, that you can use in accessibility attributes like labels or values. How cool is that? https://developer.apple.com/documentation/uikit/uicolor/accessibilityname

Created in Swift with Ignite.

Supporting Swift for Swifts