DelphiStyles.com sells stunning VCL and FireMonkey multi-device styles. In time for CodeRage, they have released two new free VCL Windows styles which can be downloaded via the GetIt Package Manager in 10.2 Tokyo. The two new free styles are "Glossy 2" and "Sky 2".
Custom styles can easily be applied via Project > Options > Appearance in RAD Studio 10.2 Tokyo.
Shown: Free Glossy 2 VCL Windows style from DelphiStyles.com
Shown: Free Glossy 2 VCL Windows style from DelphiStyles.com