Examine source code of Numix Dark GTK

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#333333",
      "tab_background_text": "#CCCCCC"
    }
  },
  "version": "2.0",
  "name": "Numix Dark GTK",
  "manifest_version": 2,
  "description": "A dark theme that's easy on the eyes with a nice clean color to match the Numix Dark GTK Theme. That's #2D2D2D to be exact."
}