I think a big factor with color themes is actually the monitor settings. I have my monitor tuned for dark mode everywhere. If I put a light theme on, the contrast doesn't look right and I go back to dark themes. Maybe it's a result of my fine-tuning, but the default "Visual Studio Dark" theme in VS Code is my favorite. It's a great minimalist theme. And I've even tried a lot of the minimalist themes suggested in this thread.