Examine source code of scaling grid

{
  "theme": {
    "images": {
      "theme_frame": "scaling_grid_h.png"
    },
    "colors": {
      "frame": "#0000ff",
      "tab_background_text": "#ffff00"
    }
  },
  "version": "2.0",
  "name": "scaling grid",
  "manifest_version": 2,
  "description": "background pattern scaling grid tiled - black background with green lines crossing building a grid of squares"
}