NewPipe/app/src/main/res/drawable-night/ic_add.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:tint="#FFFFFF"
    android:viewportWidth="24.0"
    android:viewportHeight="24.0">
    <path
        android:fillColor="#FF000000"
        android:pathData="M19,13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z" />
</vector>