Examine source code of gretsky

{
  "theme": {
    "images": {
      "theme_frame": "greta.jpg"
    },
    "colors": {
      "frame": "#031204",
      "tab_background_text": "#bac"
    }
  },
  "version": "2.0",
  "name": "gretsky",
  "manifest_version": 2,
  "description": "green-eyed cat with a green-glassed beer"
}