Windows/Visual Styles/Aero Lite
A version of this theme with Windows Aero effects is hidden in Windows 8 build 7989. It can be unlocked with two methods.
Aero Lite is also present in builds 8102, 8250 and 8400 of Windows 8. Translucency can be enabled in the Consumer Preview and the Release Preview by means of a bug in the Personalization Control Panel.