Examine source code of Agent_Shadow

{
  "theme": {
    "images": {
      "theme_frame": "AgentShadow-Header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#002163"
    }
  },
  "version": "2.0",
  "name": "Agent_Shadow",
  "manifest_version": 2,
  "description": "This is a header I've made based on my animated film 'Agent: Shadow', which I show on my You Tube channel!"
}