Examine source code of anim-pixel city

{
  "name": "pixel city",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "1520035740_file.gif"
    },
    "colors": {
      "frame": "rgba(114, 102, 247, 1)",
      "tab_background_text": "rgba(75, 130, 214, 1)",
      "toolbar": "rgba(158, 155, 209, 1)",
      "bookmark_text": "rgba(14, 42, 153, 0.65)",
      "toolbar_field": "rgba(209, 192, 250, 1)",
      "toolbar_field_text": "rgba(145, 145, 189, 1)"
    }
  }
}