Examine source code of MCFC Mosaic

{
  "name": "MCFC Mosaic",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "Screen Shot 2019-05-07 at 17_opt.png"
    },
    "colors": {
      "frame": "rgba(143, 172, 230, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(255, 255, 255, 0.45)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(255, 255, 255, 0.67)"
    }
  }
}