Attempt to invoke virtual method 'void android.graphics.drawable.Drawable.setColorFilter(int, android.graphics.PorterDuff$Mode)' on a null object reference at pl..smok.ui.activity.MainActivity$2.onTabUnselected(MainActivity.java:163)

Stack trace

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.drawable.Drawable.setColorFilter(int, android.graphics.PorterDuff$Mode)' on a null object reference
                                                                            at pl..smok.ui.activity.MainActivity$2.onTabUnselected(MainActivity.java:163)
	at android.support.design.widget.TabLayout.dispatchTabUnselected(TabLayout.java:1163)
	at android.support.design.widget.TabLayout.selectTab(TabLayout.java:1149)
	at android.support.design.widget.TabLayout.selectTab(TabLayout.java:1124)
	at android.support.design.widget.TabLayout$Tab.select(TabLayout.java:1419)
	at android.support.design.widget.TabLayout$TabView.performClick(TabLayout.java:1524)
	at android.view.View$PerformClick.run(View.java:22526)
	at android.os.Handler.handleCallback(Handler.java:739)
	at android.os.Handler.dispatchMessage(Handler.java:95)
	at android.os.Looper.loop(Looper.java:158)
	at android.app.ActivityThread.main(ActivityThread.java:7224)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)