Examine source code of sweet-dark-gradient

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "sweet-dark-gradient",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top",
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(12, 14, 20)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(22, 25, 37)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(22, 25, 37)",
      "toolbar_field_text": "rgb(255, 0, 230)",
      "tab_line": "rgb(88, 0, 226)",
      "popup": "rgb(22, 25, 37)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(88, 0, 226)",
      "button_background_hover": "rgb(255, 0, 230)",
      "icons_attention": "rgb(255, 0, 248)",
      "ntp_background": "rgb(12, 14, 20)",
      "ntp_text": "rgb(255, 255, 255)",
      "popup_border": "rgb(255, 0, 230)",
      "popup_highlight": "rgba(255, 0, 230, 0.75)",
      "tab_loading": "rgb(0, 255, 179)",
      "toolbar_field_border_focus": "rgb(255, 0, 230)",
      "toolbar_field_border": "rgb(88, 0, 226)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgb(88, 0, 226)"
    }
  }
}