Examine source code of Basic Grey

{
  "theme": {
    "images": {
      "theme_frame": "F_header.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#cccccc"
    }
  },
  "version": "2.0",
  "name": "Basic Grey",
  "manifest_version": 2,
  "description": "It's just a basic grey-like persona. Cause I like what is very simple, what do not hurt the eyes !"
}