Examine source code of Marble Rock

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Marble Rock",
  "manifest_version": 2,
  "description": "Marble texture abstract theme.\n\nMarble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite."
}