The one of the easiest ways to create custom styled Dialog in Android is to hide title and set xml layout in content. For example:

final Dialog dialog = new Dialog(MainActivity.this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.dialog_select_action_new);
dialog.show();

requestWindowFeature

method is need to be set before

setContentView

And in

dialog_select_action_new.xml

file we have freedom to make any modifications, just like this:

<?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"
    android:background="#f0f7fa"
    android:minWidth="350dp"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:background="#97c7dc"
        android:orientation="vertical" >

        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:text="@string/add_event_title"
            android:textColor="#ffffff"
            android:textSize="20sp"
            android:textStyle="bold" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#f0f7fa"
        android:orientation="vertical"
        android:padding="10dp" >

        <Button
            android:id="@+id/dialog_select_fun_btn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/btn_add_fun"
            android:drawableLeft="@drawable/fun_icon"
            android:drawablePadding="10dp"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:text="@string/add_event_fun_btn"
            android:textColor="#ffffff" />

        <Button
            android:id="@+id/dialog_select_ill_btn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:background="@drawable/btn_add_fun"
            android:drawableLeft="@drawable/baby_health_icon"
            android:drawablePadding="10dp"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:text="@string/add_event_fun_ill"
            android:textColor="#ffffff" />
    </LinearLayout>
</LinearLayout>

Final result is:

ps: The big plus from that is on android 2.x devices dialog looks like android 4.x version.