Examine source code of Modern Dark

{
  "manifest_version": 2,
  "version": "1.5resigned1",
  "name": "Modern Dark",
  "theme": {
    "colors": {
      "toolbar": "rgb(31,31,31)",
      "toolbar_field": "rgb(55,55,55)",
      "toolbar_field_text": "#fafafa",
      "toolbar_field_border": "rgb(31,31,31)",
      "toolbar_field_border_focus": "rgb(31,31,31)",
      "toolbar_top_separator": "rgb(31,31,31)",
      "toolbar_bottom_separator": "rgb(55,55,55)",
      "toolbar_vertical_separator": "rgb(99,99,99)",
      "toolbar_text": "#fafafa",
      "bookmark_text": "#fafafa",
      "tab_line": "rgb(31,31,31)",
      "tab_loading": "rgb(35,153,255)",
      "tab_background_separator": "rgb(99,99,99)",
      "ntp_background": "rgb(31,31,31)",
      "ntp_text": "#fafafa",
      "accentcolor": [
        55,
        55,
        55
      ],
      "frame": [
        55,
        55,
        55
      ],
      "text_color": [
        250,
        250,
        250
      ],
      "tab_background_text": "#fafafa",
      "icons": "#d0d0d0",
      "icons_attention": "rgb(35,153,255)",
      "button_background_hover": "hsla(0,0%,75%,.15)",
      "button_background_active": "hsla(0,0%,75%,.25)",
      "popup": "rgb(55,55,55)",
      "popup_border": "rgb(55,55,55)",
      "popup_text": "#fafafa",
      "popup_highlight": "rgba(35,153,255, 0.5)",
      "popup_highlight_text": "white",
      "sidebar": "rgb(31,31,31)",
      "sidebar_border": "rgb(55,55,55)",
      "sidebar_text": "#fafafa",
      "sidebar_highlight": "rgba(35,153,255, 0.5)",
      "sidebar_highlight_text": "white"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dd3e0435-f6b2-4a2a-b5fa-f6b8d31cd91c}"
    }
  }
}