Examine source code of collage 2

{
  "theme": {
    "images": {
      "theme_frame": "firefoxskin1.jpg"
    },
    "colors": {
      "frame": "#f27f0c",
      "tab_background_text": "#f27f0c"
    }
  },
  "version": "2.0",
  "name": "collage 2",
  "manifest_version": 2
}