Examine source code of Netscape 3 Classic FF Light

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Netscape Navigator Classic Animation",
  "description": "Modern Firefox light theme with the classic Netscape 3 loading animation in the top right corner",
  "browser_specific_settings": {
    "gecko": {
      "id": "netscape-theme@classic.example.com",
      "strict_min_version": "60.0"
    }
  },
  "theme": {
    "images": {
      "theme_frame": "images/Netscape_3_verytall.gif"
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(247, 247, 247)",
      "toolbar_text": "rgb(24, 24, 24)",
      "frame": "rgb(229, 229, 229)",
      "tab_background_text": "rgb(24, 24, 24)",
      "toolbar_field": "rgb(240, 240, 244)",
      "toolbar_field_text": "rgb(24, 24, 24)",
      "toolbar_field_focus": "white",
      "toolbar_field_text_focus": "black",
      "tab_line": "transparent",
      "popup": "white",
      "popup_text": "rgb(24, 24, 24)"
    }
  },
  "icons": {
    "48": "images/netscape-icon.png",
    "96": "images/netscape-icon.png"
  }
}