Examine source code of Overcast

{
  "theme": {
    "images": {
      "theme_frame": "google3.jpeg"
    },
    "colors": {
      "frame": "#0009ff",
      "tab_background_text": "#2c3187"
    }
  },
  "version": "2.0",
  "name": "Overcast",
  "manifest_version": 2,
  "description": "I was bored, and this came to me.... hope you like it?"
}