Examine source code of A nice theme

{
  "name": "A nice theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "cool-pictures-2018-2.jpg"
    },
    "colors": {
      "frame": "rgba(48, 63, 97, 1)",
      "tab_background_text": "rgba(230, 37, 37, 1)",
      "toolbar": "rgba(235, 91, 18, 1)",
      "bookmark_text": "rgba(214, 13, 13, 1)",
      "toolbar_field": "rgba(5, 235, 24, 1)"
    }
  }
}