Android Toolbar返回按钮颜色修改

//以下三行是修改回退按钮为白色的逻辑
        Drawable upArrow = ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_material);
        upArrow.setColorFilter(getResources().getColor(R.color.white), PorterDuff.Mode.SRC_ATOP);
        getSupportActionBar().setHomeAsUpIndicator(upArrow);