Examine source code of Comet Firefox

{
  "theme": {
    "images": {
      "theme_frame": "cometfirefox_header.jpg"
    },
    "colors": {
      "frame": "#f2e4e4",
      "tab_background_text": "#f2e4e4"
    }
  },
  "version": "2.0",
  "name": "Comet Firefox",
  "manifest_version": 2,
  "description": "Firefox as a fiery comet with starry sky background"
}