Examine source code of Spring_21

{
  "theme": {
    "images": {
      "theme_frame": "sunset.jpg"
    },
    "colors": {
      "frame": "#fc0fd1",
      "tab_background_text": "#000"
    }
  },
  "version": "2.0",
  "name": "Spring_21",
  "manifest_version": 2
}