We have today changed the default theme for Voice sites to Bootstrap.
This will affect all newly created sites, and will also change the theme on sites that have never changed their theme.
We strongly recommend that you use the Bootstrap or Modern themes for all sites, as these are fully compatible with mobile and iPad browsers, and will also help with your site's search engine ranking. These themes are very customisable with lots of options for colour schemes and layouts. We recommend you try the different colour schemes in these themes before trying the other themes.
The other themes are still available on Voice, and can be selected if you wish. (The previous default theme was DarkTones, so if you are particularly fond of that then you can stick with it!)
Joe - Voice Admin