I’ve created a new theme by adopting the theme Mac Classic that is shipped with TextMate. The original Mac Classic is a light theme, this new theme is adopted for the dark mode setting in macOS Mojave.
Since I’m not a designer I took an engineering approach to creating this theme. I took the basic colors for background, foreground and similar from Xcode. Then I wrote a script that parses the Mac Classic theme file, extracts the colors, converts the colors to HSB and adjusts the saturation and brightness. Then it writes the new colors back to an a new file. I then did some tweaks manually for some colors. I think it turned out pretty good. The theme is available here [1].