Examine source code of hot&cold_0.1

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "darkish theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg",
        "images/1.jpg",
        "images/2.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center",
        "center center",
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "no-repeat",
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(27, 40, 45)",
      "toolbar_text": "rgb(233, 242, 44)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(132, 181, 32)",
      "toolbar_field": "rgb(240, 187, 53)",
      "toolbar_field_text": "rgb(53, 51, 236)",
      "tab_line": "rgb(41, 240, 39)",
      "popup": "rgb(82, 59, 59)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(41, 240, 39)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3b3b77c3-3bff-4def-86d1-fcd66f6c3116}"
    }
  }
}