Android custom style not showing on a LinearLayout
<style name="Dialog"
    parent="@android:style/Theme.Dialog">
    <item name="android:windowBackground">@null</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:shadowColor">#FF000000</item>
    <item name="android:shadowDx">10</item>
    <item name="android:shadowDy">10</item>
    <item name="android:shadowRadius">10</item>
  </style>

<?xml version="1.0" encoding="utf-8"?>
<!-- custom dialog -->
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/layout_root"
  android:orientation="vertical"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:gravity="center"
  android:background="@color/grey"
  style="@style/Dialog">
...

public CustomDialog create() {
            Typeface tf = Typeface.createFromAsset(context.getAssets(), "fonts/IMPACT.TTF");

            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            // instantiate the dialog with the custom Theme
            final CustomDialog dialog = new CustomDialog(context, R.style.Dialog);

            View layout = inflater.inflate(R.layout.custom_dialog, null);
            dialog.addContentView(layout, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
            dialog.setContentView(layout);

            TextView text = (TextView) layout.findViewById(R.id.text);
            text.setTypeface(tf);
            text.setText("Add this game to your cal, or share it on Facebook.");

            return dialog;
        }

final CustomDialog dialog = new CustomDialog(context, R.style.Dialog);