Zeonica is a colorful and (hopefully) aesthetically-pleasing original theme designed by Andrew Vallette. It is currently available for Microsoft Visual Studio Code, but more development environments will be supported in the future.
Getting this theme installed in Visual Studio Code is easy. Simply navigate to the Extensions page and search for Zeonica. After it comes up, select it, click Install, and then reload the window (by clicking Reload). Next, access the Color Themes menu by pressing Ctrl+K, Ctrl+T (or via the File -> Preferences -> Color Themes menu). Select Zeonica, and you're done!