Examine source code of Ultrakill wrath thing

{
  "name": "Ultrakill",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Ultrablue.png"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(0, 238, 255, 1)",
      "toolbar": "rgba(255, 255, 255, 0)",
      "toolbar_field": "rgba(255, 255, 255, 1)",
      "toolbar_field_text": "rgba(43, 148, 240, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{013b3225-f39a-42f2-a6fc-120fddd257c4}"
    }
  }
}