Why are jsonc keys and values the same color?

[Avasam]

It makes it harder to differentiate keys from values

// Comment is invalid
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
}

vs

// Comments are fine
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
}

[lildude]

This is a syntax highlighting design question so really should be directed to the upstream maintainers.

From the troubleshooting docs:

There's a problem with the syntax highlighting of a file

Linguist detects the language of a file but the actual syntax-highlighting is powered by a set of language grammars which are included in this project as a set of submodules as listed here.

If you experience an issue with the syntax-highlighting on GitHub, please report the issue to the upstream grammar repository, not here. Grammars are updated every time we build the Linguist gem so upstream bug fixes are automatically incorporated as they are fixed.

[Avasam]

Ah, thanks for the link. There's the issue: JSON with comments is using javascript parsing. So it thinks it's just 2 strings (js string key) and makes no difference.

JSON with Comments: atom/language-javascript

// js
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
  valid:"js",
}

// jsonc
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
  invalid:"json with comment",
}

// json5
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
  valid:"json5",
}

// json
{
  "foo": "bar",
  "foo2": true,
  "foo3": 3,
  invalid:"json",
}

Sidenote, that repo is about to be archived and abandoned in ~2 weeks.