公认的答案是更基于每个样式的东西，但最有效的做法是在你的AppTheme样式中添加colorAccent属性，像这样:

<style name="AppTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:editTextStyle">@style/EditTextStyle</item>
</style>

<style name="EditTextStyle" parent="Widget.AppCompat.EditText"/>

colorAccent属性用于在整个应用程序中为小部件着色，因此应该用于一致性

下面是TextInputLayout在支持设计库中的部分源代码(更新为23.2.0版本)，它以更简单的方式改变EditText的底线颜色:

private void updateEditTextBackground() {
    ensureBackgroundDrawableStateWorkaround();

    final Drawable editTextBackground = mEditText.getBackground();
    if (editTextBackground == null) {
        return;
    }

    if (mErrorShown && mErrorView != null) {
        // Set a color filter of the error color
        editTextBackground.setColorFilter(
                AppCompatDrawableManager.getPorterDuffColorFilter(
                        mErrorView.getCurrentTextColor(), PorterDuff.Mode.SRC_IN));
    }
    ...
}

在23.2.0中，如果您想通过编程方式更改颜色，上述所有代码似乎都变得毫无用处。

如果你想支持所有平台，以下是我的方法:

/**
 * Set backgroundTint to {@link View} across all targeting platform level.
 * @param view the {@link View} to tint.
 * @param color color used to tint.
 */
public static void tintView(View view, int color) {
    final Drawable d = view.getBackground();
    final Drawable nd = d.getConstantState().newDrawable();
    nd.setColorFilter(AppCompatDrawableManager.getPorterDuffColorFilter(
            color, PorterDuff.Mode.SRC_IN));
    view.setBackground(nd);
}

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>

    <item name="colorControlNormal">@color/colorAccent</item>
    <item name="colorControlActivated">@color/colorAccent</item>
    <item name="colorControlHighlight">@color/colorAccent</item>

</style>

非常简单，只需在EditText中添加android:backgroundTint属性。

android:backgroundTint="@color/blue"
android:backgroundTint="#ffffff"
android:backgroundTint="@color/red"


 <EditText
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:backgroundTint="#ffffff"/>

这个问题完全把我难住了。我已经在这个线程中尝试了所有的东西，但无论我做什么，我都不能改变下划线的颜色，除了默认的蓝色。

I finally figured out what was going on. I was (incorrectly) using android.widget.EditText when making a new instance (but the rest of my components were from the appcompat library). I should have used android.support.v7.widget.AppCompatEditText. I replaced new EditText(this) with new AppCompatEditText(this) and the problem was instantly solved. It turns out, if you are actually using AppCompatEditText, it will just respect the accentColor from your theme (as mentioned in several comments above) and no additional configuration is necessary.

经过2天的斗争，我想出了一个解决这个问题的工作方案，下面的解决方案是完美的，他们想要改变少数编辑文本，通过java代码改变/切换颜色，并希望克服操作系统版本上由于使用setColorFilter()方法而导致的不同行为的问题。

    import android.content.Context;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.AppCompatDrawableManager;
import android.support.v7.widget.AppCompatEditText;
import android.util.AttributeSet;
import com.newco.cooltv.R;

public class RqubeErrorEditText extends AppCompatEditText {

  private int errorUnderlineColor;
  private boolean isErrorStateEnabled;
  private boolean mHasReconstructedEditTextBackground;

  public RqubeErrorEditText(Context context) {
    super(context);
    initColors();
  }

  public RqubeErrorEditText(Context context, AttributeSet attrs) {
    super(context, attrs);
    initColors();
  }

  public RqubeErrorEditText(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    initColors();
  }

  private void initColors() {
    errorUnderlineColor = R.color.et_error_color_rule;

  }

  public void setErrorColor() {
    ensureBackgroundDrawableStateWorkaround();
    getBackground().setColorFilter(AppCompatDrawableManager.getPorterDuffColorFilter(
        ContextCompat.getColor(getContext(), errorUnderlineColor), PorterDuff.Mode.SRC_IN));
  }

  private void ensureBackgroundDrawableStateWorkaround() {
    final Drawable bg = getBackground();
    if (bg == null) {
      return;
    }
    if (!mHasReconstructedEditTextBackground) {
      // This is gross. There is an issue in the platform which affects container Drawables
      // where the first drawable retrieved from resources will propogate any changes
      // (like color filter) to all instances from the cache. We'll try to workaround it...
      final Drawable newBg = bg.getConstantState().newDrawable();
      //if (bg instanceof DrawableContainer) {
      //  // If we have a Drawable container, we can try and set it's constant state via
      //  // reflection from the new Drawable
      //  mHasReconstructedEditTextBackground =
      //      DrawableUtils.setContainerConstantState(
      //          (DrawableContainer) bg, newBg.getConstantState());
      //}
      if (!mHasReconstructedEditTextBackground) {
        // If we reach here then we just need to set a brand new instance of the Drawable
        // as the background. This has the unfortunate side-effect of wiping out any
        // user set padding, but I'd hope that use of custom padding on an EditText
        // is limited.
        setBackgroundDrawable(newBg);
        mHasReconstructedEditTextBackground = true;
      }
    }
  }

  public boolean isErrorStateEnabled() {
    return isErrorStateEnabled;
  }

  public void setErrorState(boolean isErrorStateEnabled) {
    this.isErrorStateEnabled = isErrorStateEnabled;
    if (isErrorStateEnabled) {
      setErrorColor();
      invalidate();
    } else {
      getBackground().mutate().clearColorFilter();
      invalidate();
    }
  }
}

xml中的用法

<com.rqube.ui.widget.RqubeErrorEditText
            android:id="@+id/f_signup_et_referral_code"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_toEndOf="@+id/referral_iv"
            android:layout_toRightOf="@+id/referral_iv"
            android:ems="10"
            android:hint="@string/lbl_referral_code"
            android:imeOptions="actionNext"
            android:inputType="textEmailAddress"
            android:textSize="@dimen/text_size_sp_16"
            android:theme="@style/EditTextStyle"/>

按样式添加线条

<style name="EditTextStyle" parent="android:Widget.EditText">
    <item name="android:textColor">@color/txt_color_change</item>
    <item name="android:textColorHint">@color/et_default_color_text</item>
    <item name="colorControlNormal">@color/et_default_color_rule</item>
    <item name="colorControlActivated">@color/et_engagged_color_rule</item>
  </style>

切换颜色的Java代码

myRqubeEditText.setErrorState(true);
myRqubeEditText.setErrorState(false);