Examine source code of Rainbow behind the hill

{
  "name": "Дъга",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Дъга.jpg"
    },
    "colors": {
      "toolbar": "rgba(42, 51, 120, 0.14)",
      "toolbar_field": "rgba(120, 62, 7, 0.23)",
      "toolbar_field_text": "rgba(8, 8, 8, 1)",
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(42, 42, 79, 1)",
      "bookmark_text": "rgba(42, 42, 79, 1)"
    }
  }
}