Examine source code of Gray Helvetica

{
  "theme": {
    "images": {
      "theme_frame": "top_helvetica.jpg"
    },
    "colors": {
      "frame": "#8f8f8f",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Gray Helvetica",
  "manifest_version": 2,
  "description": "Tribute to Helvetica"
}