Set default title options when applying screen options

lib/android/app/src/main/java/com/reactnativenavigation/presentation/OptionsPresenter.java

 package com.reactnativenavigation.presentation;
 
 import android.app.Activity;
+import android.graphics.Color;
 import android.support.annotation.NonNull;
 
 import com.reactnativenavigation.interfaces.ChildDisappearListener;
 import java.util.ArrayList;
 
 public class OptionsPresenter {
+    private static final int DEFAULT_TITLE_COLOR = Color.BLACK;
+    private static final int DEFAULT_SUBTITLE_COLOR = Color.GRAY;
+
     private TopBar topBar;
 
     public OptionsPresenter(TopBar topBar) {
     private void applyTopBarOptions(TopBarOptions options, AnimationsOptions animationOptions, Component component) {
         if (options.title.text.hasValue()) topBar.setTitle(options.title.text.get());
         if (options.title.component.hasValue()) topBar.setTitleComponent(options.title.component.get(), options.title.alignment);
-        if (options.title.color.hasValue()) topBar.setTitleTextColor(options.title.color.get());
         if (options.title.fontSize.hasValue()) topBar.setTitleFontSize(options.title.fontSize.get());
+        topBar.setTitleTextColor(options.title.color.get(DEFAULT_TITLE_COLOR));
         topBar.setTitleTypeface(options.title.fontFamily);
 
         if (options.subtitle.text.hasValue()) topBar.setSubtitle(options.subtitle.text.get());
-        if (options.subtitle.color.hasValue()) topBar.setSubtitleColor(options.subtitle.color.get());
         if (options.subtitle.fontSize.hasValue()) topBar.setSubtitleFontSize(options.subtitle.fontSize.get());
+        topBar.setSubtitleColor(options.subtitle.color.get(DEFAULT_SUBTITLE_COLOR));
         topBar.setSubtitleFontFamily(options.subtitle.fontFamily);
 
         topBar.setBackgroundColor(options.background.color);

lib/android/app/src/main/java/com/reactnativenavigation/utils/UiUtils.java

         float scale = NavigationApplication.instance.getResources().getDisplayMetrics().density;
         return dp * scale + 0.5f;
     }
-
 }

playground/src/screens/OptionsScreen.js

         <Button title='Show touch through overlay' testID={testIDs.SHOW_TOUCH_THROUGH_OVERLAY_BUTTON} onPress={() => this.onClickShowOverlay(false)} />
         <Button title='Push Default Options Screen' testID={testIDs.PUSH_DEFAULT_OPTIONS_BUTTON} onPress={this.onClickPushDefaultOptionsScreen} />
         <Button title='Show TopBar react view' testID={testIDs.SHOW_TOPBAR_REACT_VIEW} onPress={this.onShowTopBarReactView} />
+        {Platform.OS === 'android' ? <Button title='Push' testID={testIDs.PUSH_BUTTON} onPress={this.onPush} /> : null}
         <Text style={styles.footer}>{`this.props.containerId = ${this.props.containerId}`}</Text>
       </View>
     );
       }
     });
   }
+
+  onPush = () => {
+    Navigation.push(this.props.componentId, {
+      component: {
+        name: 'navigation.playground.PushedScreen',
+        options: {
+          topBar: {
+            title: {
+              text: 'pushed'
+            },
+            subtitle: {
+              text: 'subtitle'
+            }
+          }
+        }
+      }
+    });
+  };
 }
 
 const styles = {