TPOV

In OWA 2007 one had the option to change the appearance of OWA (Outlook Web Access) through the “Appearance” setting under “General Settings” (in Options).

In OWA 2010 (Outlook Web App), these settings are no long present. (See also: Configure Segmentation in Outlook Web App)

Yet, all the PowerShell commands, registry settings and directory structure still exists in pretty much the same way as in OWA 2007. (Just check the Segmentation tab of the OWA (Default Web Site) properties. You’ll see it still lists “Theme Selection”.)

So, to change your theme in OWA 2010, simply put your “Theme” in the Exchange Installation folder (V14\ClientAccess\Owa\<version>\themes\<number>) and change the theme through PowerShell;

Set-OwaVirtualDirectory “OWA (Default Web Site)” –DefaultTheme <number>

Remember; this is a server wide setting, not a user specific one.