Examine source code of devGo Header

{
  "name": "devGo Header",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "devgo-Header.png"
    },
    "colors": {
      "frame": "rgba(65, 160, 250, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "toolbar_field": "rgba(64, 165, 247, 0.14)",
      "tab_line": "rgba(255, 255, 255, 0.89)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c8378cf8-9d4b-4bb3-9220-9ed629f57e0b}"
    }
  }
}