Examine source code of Steel Monster

{
  "theme": {
    "images": {
      "theme_frame": "steel-monster-head.png"
    },
    "colors": {
      "frame": "#49e30c",
      "tab_background_text": "#bac"
    }
  },
  "version": "2.0",
  "name": "Steel Monster",
  "manifest_version": 2,
  "description": "Monster claws logo icon on brushed steel background."
}