It will be a better option if u use seprate layout for toolbar and then inflate it in toolbar.In this layout you will be able to give any style size color and icon to it.
Take a new xml file app_bar layout and copy the following code in it.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorWhite">
<ImageView
android:id="@+id/btnBack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:padding="10dp"
android:text="@string/back_font"
android:textColor="@color/colorBtn"
android:textSize="30sp" />
<TextView
android:id="@+id/lblTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="8dp"
android:layout_toRightOf="@+id/btnBack"
android:text="Create Account"
android:textColor="@color/colorBtn"
android:textSize="18sp" />
</RelativeLayout>
then in your activity containing toolbar copy this code.
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
final View barview =LayoutInflater.from(this).inflate(R.layout.app_bar_register, toolbar, false);
toolbar.addView(barview);
if (toolbar != null) {
setSupportActionBar(toolbar);
}
ImageView btnBack= (ImageView) barview.findViewById(R.id.btnBack);
btnBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onBackPressed();
}
});