Examine source code of What now by willbaforce

{
  "theme": {
    "images": {
      "theme_frame": "firefoxheadertidy.jpg"
    },
    "colors": {
      "frame": "#ababab",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "What now by willbaforce",
  "manifest_version": 2,
  "description": "Persona to complement my blog's web appearance. Includes Cheburashka (on header and footer) my handle and the site's address (on footer)"
}