Change tint color of buttons in activity sharing
<p>My app uses a blueish color for the navigation bar. I set it globally in the AppDelegate like this:</p>

<pre><code>[[UINavigationBar appearance] setBarTintColor:[UIColor colorWithRed:0.0 green:0.4705882353 blue:0.7450980392 alpha:1.0]];
</code></pre>

<p>The problem is that when the user shares a PDF file via email with a <strong>UIDocumentInteractionController</strong>, the 'Cancel' and 'Send' buttons are also close to blue, which makes them almost invisible.</p>

<p><a href="https://i.stack.imgur.com/pw4b2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pw4b2.png" alt="enter image description here"></a>
I tried:</p>

<pre><code>[[UIBarButtonItem appearanceWhenContainedInInstancesOfClasses:@[[UINavigationBar class]]] setTintColor:[UIColor whiteColor]];
</code></pre>

<p>and</p>

<pre><code>[[UIButton appearanceWhenContainedInInstancesOfClasses:@[[UINavigationBar class]]] setTintColor:[UIColor whiteColor]];
</code></pre>

<p>This works everywhere else in my app, but not on screens presented from the <code>UIDocumentInteractionController</code>.
How can I change the colors of these buttons?</p>