Examine source code of Beautiful background2

{
  "name": "Beautiful background2",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Beautiful background.png"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(0, 94, 255, 0.25)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(255, 255, 255, 0.18)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(0, 34, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e7847805-12eb-48cf-ba64-1baff3561d92}"
    }
  }
}