Examine source code of Blue Sky Field

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#c7dcf5",
      "tab_background_text": "#222b23"
    }
  },
  "version": "2.0",
  "name": "Blue Sky Field",
  "manifest_version": 2,
  "description": "Serene blue sky on a warm fall day over the colors of the trees and hay field."
}