While the standard Office 2007 versions require a product key for activation, the "Blue Edition" was a leaked volume-licensed version intended for large organizations. It gained popularity because: No Activation Required
The truth was slightly more grounded but no less interesting. The "Blue Edition" was actually a leaked copy of the volume license media.
You have three legitimate paths to enjoy the classic Office 2007 interface—including a blue theme—without downloading dangerous modified editions.
Office 2007 natively supports , but cannot open files created with Office 2016, 2019, 2021, or Microsoft 365 that use newer features like dynamic arrays, XLOOKUP, or 3D models without losing data. The Blue Edition does not add these capabilities.