Examine source code of Synthwave Gradient

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Synthwave",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(35, 24, 65)",
      "toolbar_text": "rgb(126, 254, 254)",
      "frame": "rgb(124, 0, 116)",
      "tab_background_text": "rgb(111, 253, 253)",
      "toolbar_field": "rgb(1, 1, 32)",
      "toolbar_field_text": "rgb(0, 255, 177)",
      "tab_line": "rgb(235, 0, 255)",
      "popup": "rgb(31, 34, 61)",
      "popup_text": "rgb(126, 254, 254)",
      "frame_inactive": "rgb(60, 25, 77)",
      "ntp_background": "rgb(35, 24, 65)",
      "tab_loading": "rgb(235, 0, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2027e943-f27b-48db-89c4-29a831a69c3e}"
    }
  }
}