Examine source code of Sea Themes

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Sea Themes",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-012-1e971c5fbb8dec3acbd76dd6c6819de9.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 157, 238, 0.17)",
      "toolbar_text": "rgb(247, 253, 251)",
      "frame": "rgb(140, 194, 208)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(243, 247, 255)",
      "toolbar_field_text": "rgb(96, 183, 204)",
      "tab_line": "rgb(239, 255, 252)",
      "popup": "rgb(130, 220, 249)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(239, 255, 252)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{23c76e95-bdc5-4419-a02a-8afc36e92cd9}"
    }
  }
}