Examine source code of pencilcolours

{
  "theme": {
    "images": {
      "theme_frame": "Rainbow_by_dimitarmisevKopie.jpg"
    },
    "colors": {
      "frame": "#0a0909",
      "tab_background_text": "#080a05"
    }
  },
  "version": "2.0",
  "name": "pencilcolours",
  "manifest_version": 2,
  "description": "various colours"
}