Examine source code of OneDark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "OneDark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-011-d53e0d0d1538ed554a90e056a2f04eca.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(30, 33, 39)",
      "toolbar_text": "rgb(171, 178, 191)",
      "frame": "rgb(40, 44, 52)",
      "tab_background_text": "rgb(171, 178, 191)",
      "toolbar_field": "rgb(40, 44, 52)",
      "toolbar_field_text": "rgb(171, 178, 191)",
      "tab_line": "rgb(97, 175, 239)",
      "popup": "rgb(30, 33, 39)",
      "popup_text": "rgb(171, 178, 191)",
      "button_background_active": "rgba(171, 178, 191, 0.32)",
      "button_background_hover": "rgba(171, 178, 191, 0.09)",
      "frame_inactive": "rgb(30, 33, 39)",
      "icons_attention": "rgb(97, 175, 239)",
      "icons": "rgb(171, 178, 191)",
      "ntp_background": "rgb(30, 33, 39)",
      "ntp_text": "rgb(171, 178, 191)",
      "popup_border": "rgb(97, 175, 239)",
      "popup_highlight_text": "rgb(255, 255, 255)",
      "popup_highlight": "rgb(97, 175, 239)",
      "sidebar_border": "rgb(30, 33, 39)",
      "sidebar_highlight_text": "rgb(255, 255, 255)",
      "sidebar_highlight": "rgb(97, 175, 239)",
      "sidebar_text": "rgb(171, 178, 191)",
      "sidebar": "rgb(30, 33, 39)",
      "tab_background_separator": "rgb(40, 44, 52)",
      "tab_loading": "rgb(97, 175, 239)",
      "tab_selected": "rgb(30, 33, 39)",
      "tab_text": "rgb(212, 212, 212)",
      "toolbar_bottom_separator": "rgb(40, 44, 52)",
      "toolbar_field_border_focus": "rgb(97, 175, 239)",
      "toolbar_field_border": "rgb(40, 44, 52)",
      "toolbar_field_focus": "rgb(40, 44, 52)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgb(97, 175, 239)",
      "toolbar_field_separator": "rgb(255, 0, 0)",
      "toolbar_field_text_focus": "rgb(255, 255, 255)",
      "toolbar_top_separator": "rgb(30, 33, 39)",
      "toolbar_vertical_separator": "rgb(125, 129, 138)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{40ac0ce8-5200-4594-9886-6e70010eb2ef}"
    }
  }
}