Modify standard Atom syntax theme

I like Atom Dark theme, except for a couple of colors. How do I change them?
Edit theme in place? Where is it?
Or copy it to create a custom theme, and edit there? How can I do it?

You have options:

  1. Grab a raw copy of the theme from the Github project page. Copy the contents into the relevant package folder with a new name. Edit to your liking.
  2. Make a fork of the theme to your own Github account.
  3. Modify key elements in your custom style.less file.

Example for #3:

For the 1st option: In which folder can I find the theme files for Atom Dark theme?

The original project is archived here:

Press the clone or download for…

Unzip this and make the required changes. Thereafter copy it back into your own package folder.

The more recent version is here: