UITHEME:

UITHEME:
This post about new UI Themes of List Views.
Visualforce Page:

<apex:page showHeader="true" tabstyle="Case">
<apex:pageMessage severity="error" rendered="{!$User.UITheme = 'Theme3' &&
$User.UIThemeDisplayed != 'Theme3'}">
We've noticed that the new look and feel is enabled for your organization.
However, you can't take advantage of its brilliance. Please check with
your administrator for possible reasons for this impediment.
</apex:pageMessage>
<apex:ListViews type="Case" rendered="{!$User.UITheme = 'Theme3' &&
$User.UIThemeDisplayed = 'Theme3'}"/>
</apex:page>

Regular Theme: UI Theme3