Cannot resolve symbol @android:color/X anymore
<p>Before, we were able to use the android-provided colors:</p>

<pre><code>@android:color/white
</code></pre>

<p>,</p>

<pre><code>@android:color/red
</code></pre>

<p>, and</p>

<pre><code>@android:color/yellow
</code></pre>

<p>And so on.</p>

<p><strong>However,</strong> <em>THEY SUDDENLY disappeared.</em> I now get a "cannot resolve symbol '<code>@android:color/white</code>' " error. </p>

<p>What's going on? Where'd the easy-to-access colors go?</p>

<p><strong>Note:</strong> Android Studio can resolve <code>android</code>, but not <code>@android:color/white</code>.</p>