Examine source code of Dark Mode - Red Accents

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Mode with Red Accents",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(43, 42, 51)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(28, 27, 34)",
      "tab_background_text": "rgb(234, 234, 234)",
      "toolbar_field": "rgb(28, 27, 34)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgba(255, 255, 255, 0)",
      "popup": "rgb(43, 42, 51)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(210, 0, 0)",
      "button_background_hover": "rgba(210, 0, 0, 0.75)",
      "icons_attention": "rgb(210, 0, 0)",
      "popup_highlight": "rgba(210, 0, 0, 0.75)",
      "sidebar_highlight": "rgba(210, 0, 0, 0.75)",
      "tab_loading": "rgb(255, 255, 255)",
      "tab_selected": "rgba(210, 0, 0, 0.75)",
      "toolbar_bottom_separator": "rgba(255, 255, 255, 0)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgba(210, 0, 0, 0.75)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a2a4e5d-8a40-4648-a664-88941333ac1a}"
    }
  }
}