Examine source code of Hearts Forever

{
  "theme": {
    "images": {
      "theme_frame": "heartscopy.jpg"
    },
    "colors": {
      "frame": "#db0f46",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "Hearts Forever",
  "manifest_version": 2,
  "description": "Colorful Valentine hearts on a pink and purple background."
}