'Usage

Dim instance As SPWeb
Dim strNewTheme As String

instance.ApplyTheme(strNewTheme)

'Declaration

Public Sub ApplyTheme ( _
    strNewTheme As String _
)

Parameters

strNewTheme

A string that contains the template ID of a theme that is specified in the SPTHEMES.XML file of the \\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\TEMPLATE\LAYOUTS\Locale_ID folder.

The following code example applies a specified theme to a site in the current site collection.

Using webSite As SPWeb = SPContext.Current.Site.OpenWeb("Website_URL")
    webSite.ApplyTheme("Theme_ID")
End Using

Note:
Certain objects implement the IDisposable interface, and you must avoid retaining these objects in memory after they are no longer needed. For information about good coding practices, see Best Practices: Using Disposable Windows SharePoint Services Objects.