Examine source code of Rainbow Sides

{
  "name": "Rainbow Sides",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "Screenshot_2.png"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(0, 0, 0, 0.3)",
      "toolbar_field": "rgba(0, 0, 0, 0.2)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{be60894b-2b47-4a3f-aa84-c05f738cae93}"
    }
  }
}