Examine source code of The dead keep walking

{
  "name": "The dead keep walking",
  "manifest_version": 2,
  "version": "6.0",
  "theme": {
    "images": {
      "theme_frame": "zombie-night-v4.png"
    },
    "colors": {
      "frame": "rgba(120, 120, 120, 1)",
      "tab_background_text": "rgba(255, 179, 0, 1)",
      "toolbar": "rgba(80, 67, 45, 1)",
      "bookmark_text": "rgba(245, 245, 245, 1)",
      "toolbar_field": "rgba(3, 3, 3, 1)",
      "toolbar_field_text": "rgba(255, 179, 0, 1)",
      "tab_line": "rgba(255, 179, 0, 0.64)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{834556fe-baa5-4baa-8536-671e06d46a01}"
    }
  }
}