What is bootstrap config.json for?

Question

HTML

If you make customize bootstrap on the site, then along with the archive, the file falls in it with many variables of the form:

{
  "vars": {
    "@gray-base": "#000",
    "@gray": "lighten(@gray-base, 33.5%)",
    "@brand-primary": "darken(#428bca, 6.5%)",
    "@brand-success": "#5cb85c",

Is it for use in preprocessors? Because I understand that if I change some color in this file, then in the rest of the css-files it will not change anyway.

Answer 1

You can use this config to load in the same section of the bootstrap site when you need to customize your styles again. In order not to start from scratch, but to edit your previous settings.
They even write there "Have an existing configuration? Upload your config.json to import it."

Answer 2

Counter question from a newbie. is it possible to make a file with config.json settings from the existing bootstrap.css?