code: public void setArrowColor(@ColorInt int color) {
      arrowColor = color;
      arrowColorDisabled = Utils.lighter(arrowColor, 0.8f);
      if (arrowDrawable != null) {
        arrowDrawable.setColorFilter(arrowColor, PorterDuff.Mode.SRC_IN);
      }
    }
docs: Set the tint color for the dropdown arrow
  
  @param color the color value