Examine source code of Aspen Glow

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "Aspen Glow",
  "description": "Humble Gruvbox theme for Firefox 89 and newer. ",
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "89.0"
    }
  },
  "theme": {
    "colors": {
      "frame": "#282828",
      "icons_attention": "#fabd2f",
      "ntp_background": "#282828",
      "ntp_text": "#fdf4c1",
      "popup": "#3c3836",
      "popup_border": "#fabd2f",
      "popup_highlight": "#7c6f64",
      "popup_text": "#fdf4c1",
      "sidebar": "#282828",
      "sidebar_border": "#3c3836",
      "sidebar_highlight": "#7c6f64",
      "sidebar_text": "#fdf4c1",
      "tab_background_text": "#fdf4c1",
      "tab_line": "#282828",
      "tab_loading": "#fabd2f",
      "tab_selected": "#3c3836",
      "tab_text": "#fabd2f",
      "toolbar": "#282828",
      "toolbar_field": "#000000",
      "toolbar_field_border_focus": "#fabd2f",
      "toolbar_field_text": "#fdf4c1",
      "toolbar_text": "#fdf4c1",
      "toolbar_top_separator": "#282828",
      "toolbar_vertical_separator": "#282828"
    }
  }
}