Examine source code of CleanBlackTheme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "CleanBlack",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(125, 125, 125)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(200, 200, 200)",
      "toolbar_field": "rgb(56, 56, 56)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(56, 56, 56)",
      "popup_text": "rgb(255, 255, 255)",
      "icons_attention": "rgb(255, 255, 255)",
      "tab_loading": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{666f72ff-cc09-41c0-bdb5-81588ef8e4d3}"
    }
  }
}