Examine source code of c1rca..

{
  "theme": {
    "images": {
      "theme_frame": "Persona_Header_LABS.jpg"
    },
    "colors": {
      "frame": "#120101",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "c1rca..",
  "manifest_version": 2
}