Examine source code of Summer Birds

{
  "theme": {
    "images": {
      "theme_frame": "BunteVgelHeader.jpg"
    },
    "colors": {
      "frame": "#4c8767",
      "tab_background_text": "#f2efef"
    }
  },
  "version": "2.0",
  "name": "Summer Birds",
  "manifest_version": 2,
  "description": "Summer Birds Singing Sun"
}