Examine source code of Attack On Titan (BR)

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Attack On Titan (BR)",
  "manifest_version": 2,
  "description": "Tema para Mozilla Firefox do anime/mangá Attack On Titan.\n\nMozilla Firefox theme for the anime / manga Attack On Titan. (Online translation)."
}