Android Notes (2) UI text is more colorful

UI part of the code

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
       <TextView
           android:id="@+id/Tv"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="@string/app_name"/>

</LinearLayout>

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