Examine source code of Smooth Dark

{
  "theme": {
    "images": {
      "theme_frame": "top.png"
    },
    "colors": {
      "frame": "#d4d4d4",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Smooth Dark",
  "manifest_version": 2,
  "description": "This is a simple dark persona with a sleek look. It matches other software that we design."
}