Losely based on the excellent Vim theme here: https://github.com/drewtempelmeyer/palenight.vim
Matlab's editor color theming doesn't seem to be as rich as Vim or VS Code. I did what I could and it's better than Mathwork's terrible default!
Append the contents to your matlab.prf configuration file and restart Matlab.
Location can be found using prefdir at the matlab command prompt.