Is there a way to make Lazarus look like Visual Studio Code?
I can change the colors of the editor but the rest stays the same.
No you can't. With Lazarus IDE you can only change the editor syntax highlighting colors. As for any LCL based applications (that includes Lazarus IDE), you can't theme the UI separately from the OS theme. One of the many issues I have with LCL (1). If only Lazarus IDE was written in fpGUI, then everything would be 100% themeable - independent of the OS.
(1) - back in 2006 I wrote a commercial app for a client. They wanted to customise
the look of the application to stand out from other applications or the OS itself.
It wasn't possible then, and still isn't today. Luckily shortly afterwards they
decided to port everything to fpGUI. Attached or some of the theme samples
we prototyped for them. Those themes would be applied to the project even
if the program ran on Linux or Windows.