Examine source code of Cacodemon

{
  "theme": {
    "images": {
      "theme_frame": "header.PNG"
    },
    "colors": {
      "frame": "#170000",
      "tab_background_text": "#940303"
    }
  },
  "version": "2.0",
  "name": "Cacodemon",
  "manifest_version": 2,
  "description": "This is a persona for the Cacodemon from DooM, who unfortunately for him, doesn't get all the attention he deserves. Would you show him some love and applicate this persona on your FireFox browser please?"
}