Examine source code of Four Color Process

{
  "theme": {
    "images": {
      "theme_frame": "ffox_header.png"
    },
    "colors": {
      "frame": "#c7c7c7",
      "tab_background_text": "#333333"
    }
  },
  "version": "2.0",
  "name": "Four Color Process",
  "manifest_version": 2,
  "description": "Process stripes in header and 4 cmyk dots in footer. The header is a transparent .png, so don't let the preview fool you."
}