Examine source code of Overkill

{
  "theme": {
    "images": {
      "theme_frame": "OverkillHeader.jpg"
    },
    "colors": {
      "frame": "#18f50c",
      "tab_background_text": "#00ed1c"
    }
  },
  "version": "2.0",
  "name": "Overkill",
  "manifest_version": 2,
  "description": "Just a simple persona for the Band Overkill."
}