Examine source code of neo-black

{
  "name": "neo-black",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "tom-chrostek-uGXcMzBgjcs-unsplash.jpg"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(36, 36, 36, 1)",
      "toolbar": "rgba(33, 33, 33, 1)",
      "bookmark_text": "rgba(6, 214, 160, 1)",
      "toolbar_field": "rgba(0, 0, 0, 1)",
      "toolbar_field_text": "rgba(255, 228, 0, 1)",
      "tab_line": "rgba(191, 0, 255, 1)"
    }
  }
}