Examine source code of Blue in White

{
  "name": "Blue in White",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "rect31.png"
    },
    "colors": {
      "frame": "rgba(0, 77, 255, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(245, 245, 245, 1)",
      "bookmark_text": "rgba(56, 56, 56, 1)",
      "toolbar_field": "rgba(255, 255, 255, 1)",
      "toolbar_field_text": "rgba(56, 56, 56, 1)",
      "tab_line": "rgba(255, 255, 255, 0.98)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{171908f8-c064-4ae0-9bc8-4b8cc16c5087}"
    }
  }
}