jdekock/colorblinds

Requirements

• iOS 17+
• Swift 5.9+

Installation

Add Colorblinds to your project via Swift Package Manager:

https://github.com/jdekock/Colorblinds

Or add it to your Package.swift:

dependencies: [
    .package(url: "https://github.com/jdekock/Colorblinds", from: "2.0.0")
]

Example

<p align="center"> <img src="Assets/example.gif" alt="Colorblinds demo" width="250"> </p>

<table> <tr> <td width="25%"> <center>Normal</center> </td> <td width="25%"> <center>Picker</center> </td> <td width="25%"> <center>Tritanopia</center> </td> <td width="25%"> <center>Achromatopsia</center> </td> </tr> <tr> <td width="25%"> <img src="Assets/example_1.png"></img> </td> <td width="25%"> <img src="Assets/example_2.png"></img> </td> <td width="25%"> <img src="Assets/example_3.png"></img> </td> <td width="25%"> <img src="Assets/example_4.png"></img> </td> </tr> </table>

Usage

SwiftUI

Apply a specific simulation:

import Colorblinds

struct ContentView: View {
    var body: some View {
        MyAppView()
            .colorBlindSimulation(.deuteranopia)
    }
}

Bind to an optional type (nil removes the filter):

@State private var selectedType: ColorBlindType?

var body: some View {
    MyAppView()
        .colorBlindSimulation(selectedType)
}

Full simulator experience — triple-tap anywhere to open a picker sheet:

var body: some View {
    MyAppView()
        .colorBlindSimulator()
}

Note: Apply the modifier to your content views rather than to a NavigationStack or TabView. These container views use internal rendering (e.g. navigation bar materials) that conflicts with the Metal shader, resulting in a yellow warning screen.

UIKit

Full simulator experience — call start with your app's window, then triple-tap to open a picker:

import Colorblinds

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options: UIScene.ConnectionOptions) {
    guard let windowScene = scene as? UIWindowScene,
          let window = windowScene.windows.first else { return }

    ColorBlindOverlay.shared.start(in: window)
}

Direct control:

// Apply a specific simulation
ColorBlindOverlay.shared.simulate(.protanopia, in: window)

// Remove the simulation
ColorBlindOverlay.shared.stop()

Supported Types

| Type | Description | |---|---| | deuteranomaly | Reduced green sensitivity (most common) | | deuteranopia | No green cones | | protanomaly | Reduced red sensitivity | | protanopia | No red cones | | tritanomaly | Reduced blue sensitivity | | tritanopia | No blue cones | | achromatomaly | Reduced overall color sensitivity | | achromatopsia | Complete color blindness |

How It Works

• SwiftUI — Uses a [[stitchable]] Metal shader via .colorEffect(), running directly in SwiftUI's render pipeline. No screen capture, no overlay. Truly live at full frame rate.
• UIKit — Uses CADisplayLink to capture the window's layer, applies a CIColorMatrix filter on the GPU, and renders the result to an MTKView overlay.

License

MIT

Package Metadata

Repository: jdekock/colorblinds

Default branch: master

README: README.md