Expected behavior

The username changer toolbar should either be white with black icons or blue with white icons.

Actual behavior

The toolbar is white with white icons (making them invisible).

Steps to reproduce the behavior

1. Create a new account from the app.
2. On the Epilogue screen, tap on the username field.
3. Notice the Username changer screen.
4. Notice how the toolbar is not correctly styled.

Before	Now

Note: these steps were originally provided by @develric in pbMoDN-ET-p2#comment-1213