Examine source code of Celeste Core

{
  "manifest_version": 2,
  "version": "4.0",
  "name": "CelesteCore",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/Core.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left bottom"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(55, 55, 55, 0.3)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(169, 41, 195)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgba(34, 34, 34, 0.3)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(169, 41, 195)",
      "popup": "rgb(34, 34, 34)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(169, 41, 195)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8a64f0a-e797-453e-988f-c19949298f4f}"
    }
  }
}