NPE check when parsing colors

android/app/src/main/java/com/reactnativenavigation/params/parsers/StyleParamsParser.java

@@ -122,7 +122,7 @@ public class StyleParamsParser {
         if (color.hasColor()) {
             return color;
         } else {
-            return defaultColor.hasColor() ? defaultColor : color;
+            return defaultColor != null && defaultColor.hasColor() ? defaultColor : color;
         }
     }
 }