Examine source code of Subtle Proton Dark

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "Subtle Proton Dark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(43, 42, 51)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(28, 27, 34)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(28, 27, 34)",
      "toolbar_field_text": "rgb(221, 221, 221)",
      "tab_line": "rgba(43, 42, 51, 0)",
      "popup": "rgb(60, 59, 71)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(28, 27, 34)",
      "button_background_hover": "rgb(66, 65, 77)",
      "ntp_background": "rgb(28, 27, 34)",
      "popup_border": "rgb(66, 65, 77)",
      "sidebar_border": "rgb(28, 27, 34)",
      "sidebar_text": "rgb(255, 255, 255)",
      "sidebar": "rgb(43, 42, 51)",
      "tab_selected": "rgb(60, 59, 71)",
      "toolbar_bottom_separator": "rgb(28, 27, 34)",
      "toolbar_field_border": "rgba(43, 42, 51, 0)",
      "toolbar_field_focus": "rgb(60, 59, 71)",
      "toolbar_top_separator": "rgb(60, 59, 71)",
      "tab_loading": "rgba(43, 42, 51, 0)"
    }
  }
}