Examine source code of Linux Theme!

{
  "name": "Linux_-_Tux-512_40",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "ubuntu-logo32.png"
    },
    "colors": {
      "toolbar": "rgba(224, 224, 224, 1)",
      "toolbar_field": "rgba(237, 246, 255, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "frame": "rgba(0, 25, 79, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "bookmark_text": "rgba(0, 0, 0, 1)"
    }
  }
}