Examine source code of Oilseed Rape Field

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#e9bf85",
      "tab_background_text": "#090708"
    }
  },
  "version": "2.0",
  "name": "Oilseed Rape Field",
  "manifest_version": 2,
  "description": "The modern-day blot on the English landscape, a field of oilseed rape, the yellow peril of early summer."
}