For those who are interested, we have enabled the option for members to choose one of several different forum themes rather than the default theme you see now. Included is the theme we were using before the upgrade, 'Classic YaBB SE', although currently the emoticons are not visible with that theme choice. We are working on fixing this issue. There are a couple of other theme choices available which you can preview, so you might want to take a look and see which you like best.
To change the theme, follow this path:
Profile
Modify Profile
Look and Layout
And then select change for a menu of themes.
The option will look as in the attached photo.