Problem in the style.xml file Android Android

With these latest Android Studio updates I'm surprised in the project's styles.xml file that the theme is red, as can be seen in the image below:

CODE

<!--Baseapplicationtheme.--><stylename="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

<style name="MyButton" parent="AppTheme">
    <item name="colorControlHighlight">@color/colorPrimary</item>
    <item name="colorButtonNormal">@color/colorPrimaryDark</item>
    <item name="android:textColor">@drawable/button_disabled</item>
</style>

<style name="AppTheme.Fullscreen" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowFullscreen">true</item>
</style>

Even when I generate a new project in Android Studio the style.xml file stays that way.

Does anyone know if there are any bugs or how to fix this?

The version of Android Studio I have here is 3.1.1.