Examine source code of Forest Horses

{
  "name": "Forest Horses",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "forest horse theme.png"
    },
    "colors": {
      "frame": "rgba(75, 110, 23, 1)",
      "tab_background_text": "rgba(249, 249, 172, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "bookmark_text": "rgba(249, 249, 172, 1)",
      "toolbar_field": "rgba(73, 110, 22, 0.07)",
      "toolbar_field_text": "rgba(249, 249, 172, 1)",
      "tab_line": "rgba(57, 212, 30, 1)"
    }
  }
}