原地址:http://stackoverflow.com/questions/26788464/how-to-change-color-of-the-back-arrow-in-the-new-material-theme/26837072#26837072
这个返回按钮一直不是白色,一直是黑色,下面的代码,R.color.grey换成想要的颜色,我的就换成R.color.white
final Drawable upArrow = getResources().getDrawable(R.drawable.abc_ic_ab_back_mtrl_am_alpha);
upArrow.setColorFilter(getResources().getColor(R.color.grey), PorterDuff.Mode.SRC_ATOP);
getSupportActionBar().setHomeAsUpIndicator(upArrow);