If you're looking for an ethereal, whimsical look for your next project, then check out the Stellar FMX Style. This style is easy to use and it looks great on Linux through Delphi 10.3 Rio's new FMXLinux.
You can get FMX Style - Stellar 1.0 by installing it from the GetIt Package Manager.
Next, use a TStyleBook to include the Linux version of the Stellar FMX style, found in your Styles folder.
Here are some samples of the Stellar style:
Stellar also looks great in Windows, iOS, Android, and macOS projects. If you are building VCL for Windows, then check out the VCL Style - Stellar 1.0, available in the GetIt Package Manager.