electron-cannon theme
A smooth dark theme built mainly for C# programming. But, can obviously be used with any language, especially with a little bit of customisation.
If you would like to customise this theme, check out the colors.less file. My comments are based on my findings in a small sample of languages, including: .cs .cpp .html .css .js .json .py So there may be a few issues with the comments, but still may help with any customisation. If any elements appear black, check the colors.less file, it is explained.