Examine source code of Clean Dark Gray

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Clean Dark Gray",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(42, 42, 42)",
      "toolbar_text": "rgb(228, 228, 228)",
      "frame": "rgb(24, 24, 24)",
      "tab_background_text": "rgb(193, 193, 193)",
      "toolbar_field": "rgb(42, 42, 42)",
      "toolbar_field_text": "rgb(228, 228, 228)",
      "tab_line": "rgba(0, 0, 0, 0)",
      "popup": "rgb(24, 24, 24)",
      "popup_text": "rgb(228, 228, 228)",
      "popup_border": "rgba(50, 50, 50, 0)",
      "popup_highlight": "rgb(50, 50, 50)",
      "toolbar_field_border_focus": "rgba(0, 0, 0, 0)",
      "tab_loading": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5039185b-839d-4ac3-90c0-e17bf1b43c46}"
    }
  }
}