Is there a way for Unity to work with the iOS’s “Accessibility” options, such as relaying some information to the voice-over, or changing texture to black and white if that option is picked.
This is the Accessibility I am referring to
Even if I cant relay information, if I can tell if these iOS features are turned on, I could possibly emulate them manually, maybe the voice-over using
This is probably too late for your game, but maybe it can help others:
There is a plugin called UAP that recreates screen reader functionality for Unity UI. It works like VoiceOver and TalkBack, and actually uses the native VoiceOver speech for text-to-speech output.
Here’s the asset store link:
By default, games made with Unity are incompatible with screen readers because Unityʼs UI systems are not accessible to assistive technologies. This means that while the screen reader is on, it is impossible to interact with a Unity game.
This problem can be partially solved by simulating screen reader behavior with the help of text-to-speech. However, screen reader users will still have to turn their screen reader off if they want to play a game made with Unity.
The good news is that starting with Unity 6, games made with Unity can natively support screen readers by leveraging Unity’s new accessibility APIs! 
These APIs are independent of the UI, so they can be used regardless of what UI system the game employs. They are currently available for the Android and iOS runtimes, and we are actively working to extend their support to the Windows and macOS runtimes as well.
Additionally, we added APIs for retrieving certain system accessibility settings so that games made with Unity can adapt their UI according to the settings that users have configured on their devices.
Check out our blog post, documentation, and sample project.