Examine source code of Simple Drupal

{
  "theme": {
    "images": {
      "theme_frame": "persona_header.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Simple Drupal",
  "manifest_version": 2,
  "description": "This is a persona for anyone that loves Drupal. It's nice and simple with a dark blue to light blue gradient with the Drupal drop in the header and \"Drupal\" in the footer."
}