Examine source code of Grave it

{
  "theme": {
    "images": {
      "theme_frame": "Grave_It_Kopfzeile_Muster.png"
    },
    "colors": {
      "frame": "#8a8585",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Grave it",
  "manifest_version": 2
}