title: How to set TextInputLayout error message colour?
body: <p>How can I change the colour of the error message that can be set to appear below the text field in a <code>TextInputLayout</code> (via <code>setError(...)</code> – <a href="https://material-design.storage.googleapis.com/publish/material_v_4/material_ext_publish/0Bzhp5Z4wHba3Z2tnU1NHUkg1NWc/components_textfields_single4.png">see error state here</a>)?</p>
  
  <p>It normally shows as a red colour, which I want to change. Which item names/keys should I use in my <code>styles.xml</code> file to target the colour?</p>
  
  <p>Thanks in advance.</p>
  
  <p><br>
  <strong>Edit:</strong></p>
  
  <p>Added <code>app:errorTextAppearance</code> key to my <code>TextInputLayout</code>:</p>
  
  <pre><code>&lt;android.support.design.widget.TextInputLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_marginTop="8dp"
          android:id="@+id/welcome_current_week_container"
          app:errorTextAppearance="@style/WelcomeErrorAppearance"&gt;
          &lt;EditText
              ..../&gt;
      &lt;/android.support.design.widget.TextInputLayout&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>and the error appearance <em>(set to green for testing)</em>:</p>
  
  <pre><code>&lt;style name="WelcomeErrorAppearance" parent="@android:style/TextAppearance"&gt;
      &lt;item name="android:textColor"&gt;@android:color/holo_green_dark&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>The result is that the hint as well as the error message is coloured <em>(screenshots from scaled Android Emulator)</em>:</p>
  
  <p><em>Regular (no error):</em></p>
  
  <p><a href="https://i.stack.imgur.com/h9FZi.png"><img src="https://i.stack.imgur.com/h9FZi.png" alt="Before Image"></a></p>
  
  <p><em>Error state:</em></p>
  
  <p><a href="https://i.stack.imgur.com/nSlso.png"><img src="https://i.stack.imgur.com/nSlso.png" alt="After Image"></a></p>
  
  <p><strong>Edit 2/Outcome:</strong></p>
  
  <p>When the error message appears, the hint above the field changes to the same colour as the error message, overriding hint colour – this is by design.</p>