The style used for standard Salesforce pages associated with the specified object is automatically inherited by any page associated with a standard controller. That is, the tab for the supplied object is selected, and all page elements are styled with the tab's associated colour.
The tabStyle parameter on the
<apex: page> element can be used to change the styling of a page that utilizes a standard controller. The following page, for example, utilizes the Account standard controller but outputs a page that accentuates the Opportunities tab and uses the yellow colour of the Opportunity tab:
<apex:page standardController="acunt" tabStyle="opp">
</apex:page>?