Examine source code of Green Grass ...

{
  "theme": {
    "images": {
      "theme_frame": "greengrass1.jpg"
    },
    "colors": {
      "frame": "#a1fcfa",
      "tab_background_text": "#cafcf7"
    }
  },
  "version": "2.0",
  "name": "Green Grass ...",
  "manifest_version": 2,
  "description": "Love Nature..."
}