You can set a custom color for the flash message in the showMessage method of the react-native-flash-message library by passing an options object as the second argument, and including the backgroundColor property.

For example:

import FlashMessage from "react-native-flash-message"; FlashMessage.showMessage({ message: "My custom message", type: "success", }, { backgroundColor: "#00ff00" });

This will display the flash message with a green background.