Examine source code of Dark Blue 2

{
  "theme": {
    "images": {
      "theme_frame": "bluefirefox.png"
    },
    "colors": {
      "frame": "#2e4c6d",
      "tab_background_text": "#2e4c6d"
    }
  },
  "version": "2.0",
  "name": "Dark Blue 2",
  "manifest_version": 2,
  "description": "Simply dark blue"
}