Examine source code of Material Blue Grey Theme

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "Material Blue Grey Theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-037-b73f9b34467ba541de861f5b4c0c6316.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(207, 216, 220)",
      "toolbar_text": "rgb(38, 50, 56)",
      "frame": "rgb(38, 50, 56)",
      "tab_background_text": "rgb(144, 164, 174)",
      "toolbar_field": "rgb(236, 239, 241)",
      "toolbar_field_text": "rgb(38, 50, 56)",
      "tab_line": "rgba(0, 0, 0, 0)",
      "popup": "rgb(236, 239, 241)",
      "popup_text": "rgb(38, 50, 56)",
      "tab_text": "rgb(38, 50, 56)",
      "tab_loading": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{96fb9ad7-2d78-400e-940e-640daa81780b}"
    }
  }
}