Examine source code of Colorful Theme

{
  "name": "Cosmic",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "204581-960x960-color-spectrum.jpg"
    },
    "colors": {
      "frame": "rgba(75, 124, 232, 1)",
      "tab_background_text": "rgba(255, 13, 13, 1)",
      "bookmark_text": "rgba(76, 240, 255, 1)",
      "toolbar_field": "rgba(248, 255, 122, 1)",
      "toolbar_field_text": "rgba(186, 167, 167, 1)"
    }
  }
}