If you create a site using the Blank template and go to Settings > Site Theme you get a simple page that lets you set your site theme.
If you create a site using the Team Site template and go to Settings > Site Theme, you get a more advanced page.
Both these experiences are supported by the one page (/_layouts/themeweb.aspx). So what gives?
Well, themeweb.aspx contains two delegates placeholders, and there is a feature EnhancedTheming (ID: 068BC832-4951-11DC-8314-0800200C9A66) that contains controls to insert to them. This feature is hidden, but is used by a lot of the site templates – but not Blank sites. It’s also required by the publishing features.
(Actually, this feature is stapled to most of the site templates by the BaseSiteStapling feature)
So, could we turn this on for a Blank site? Obviously we can’t through the UI, but STSADM should let us.
stsadm -o activatefeature -name enhancedtheming -url [site url]
And voila! A Blank site with enhanced theming!
So why this structure? I know that the enhanced theming isn’t part of SharePoint Foundation, so having a feature that staples it to Site Definitions in full SharePoint makes sense. However, I must confess, I’m puzzled why is isn’t also stapled to ‘Blank’ sites. I guess that maybe it’s to try and keep Blank sites, um, blank.