[loikfb]

buttonColor only applied to the Android modal. On iOS the sheet's buttons were always the system blue, which clashes with apps that use their own tint.

• iOS: when buttonColor is set, the modal's alert controller uses it as its tint (Confirm and Cancel).
• The black/white default derived from theme now applies only on Android. iOS gets buttonColor only when the app passes one, so existing iOS users see no change.
• iOS 26 fills the preferred (Confirm) action with the tint under a white label, which is unreadable on light colors. For a light buttonColor the label turns black (UIAlertAction's titleTextColor key, guarded by @try).
• README and typings: no longer Android-only.

Tested on iOS 26 and iOS 18 (light and dark, with and without buttonColor) and on Android 16, React Native 0.84, new architecture.

[loikfb]

A note on the iOS 26 part, since it uses a private key: titleTextColor on UIAlertAction.

On iOS 26 the preferred action (Confirm) is filled with the tint under a white label. With a light buttonColor, typically in dark mode, that label becomes unreadable. UIKit has no public API to change it. I tried the public alternative of not setting preferredAction when the color is light. Confirm then becomes a plain grey button with a white label, like Cancel, so the color no longer shows at all.

The key is only set on iOS 26, only for a light buttonColor, and inside @try. If Apple removes it, the label falls back to white. If you'd rather keep private keys out of the library, I'm happy to drop that block. The rest of the PR stands on its own.