Changing tint color of Android EditText programmatically
With the newly introduced android.support.v4.graphics.drawable.DrawableCompat#setTint
setting the color is now possible.
This works for me:
editText.getBackground().setColorFilter(getResources().getColor(R.color.your_color),
PorterDuff.Mode.SRC_ATOP);
Source: Changing EditText bottom line color with appcompat v7