compile 'com.android.support:appcompat-v7:23.1.0'

 NightOwl.builder().defualt(MainApplication.sDefualtMode).create();

public class DemoActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // step1 before super.onCreate
        NightOwl.owlBeforeCreate(this);
        
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_demo);
        
        // step2 after setContentView
        NightOwl.owlAfterCreate(this);
        
        // write your code
    }
    
    @Override
    protected void onResume() {
        super.onResume();
        
        // step3 onResume
        NightOwl.owlResume(this);
    }
    
}

// layout.xml
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/large_text"
    android:textColor="#000000"
    night:night_textColor="#999999"
    />

// layout.xml
<TextView
    android:id="@+id/title"
    android:style="@style/MyTextStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

// style.xml
<style name="MyTextStyle">
    <item name="android:textColor">#002fff</item>
    <item name="night_textColor">#fc575d</item>
    <item name="android:background">#fdceb7</item>
    <item name="night_background">#3d1416</item>
</style>

// layout.xml
<TextView
    android:textAppearance="@style/TextPrimary"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

// style.xml
<style name="TextPrimary" parent="TextAppearance.AppCompat.Title">
    <item name="android:textColor">#FF000000</item>
    <item name="night_textColor">#4d4d4d</item>
</style>

public class CustomView extends View implements IOwlObserver {
  @Override
    public void onSkinChange(int mode, Activity activity) {
        int color = mode == 0 ? mColor : mColorNight;
        mPaint.setColor(color);
        this.invalidate();
    }
}

CustomView customView = new CustomView(this);
// register
NightOwl.owlRegisterCustom(customView);