Examine source code of DO1a

{
  "name": "DO1a",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "422px-Pure_black_wallpaper.jpg"
    },
    "colors": {
      "frame": "rgba(38, 38, 38, 1)",
      "tab_background_text": "rgba(194, 152, 0, 1)",
      "toolbar": "rgba(0, 0, 0, 0.22)",
      "toolbar_field": "rgba(0, 0, 0, 1)",
      "toolbar_field_text": "rgba(194, 152, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{70d277be-966e-4b23-a296-782887ea70ca}"
    }
  }
}