BottomNavigationBar-change the tab icon color

Change to app:itemIconTint="@drawable/selector"

Also change your selector.xml to this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_checked="true" android:color="@color/beyaz" />
<item android:color="@color/colorPrimaryDark"  />
</selector>

I was confused about whole process despite reading all the answers, so here is how I resolved it step by step so beginners can understand it properly

Let's say you created MainActivity with bottom navigation so

in your drawable folder create bottom_navigation_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_checked="true" android:color="@color/yourSelectedColor" />
  <item android:color="@color/defaultColor"  />
</selector>

then go to the activity_main.xml layout and add this line in BottomNavigationView

app:itemIconTint="@drawable/bottom_navigation_selector"

If you also want to change text color accordingly then you need to add this line aswell

app:itemTextColor="@drawable/bottom_navigation_selector"