Examine source code of BlueGrey theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "blue grey theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-002-609370e89a219e0548ac5ef6b4a7dd2e.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(179, 200, 207)",
      "toolbar_text": "rgb(0, 4, 4)",
      "frame": "rgb(5, 145, 203)",
      "tab_background_text": "rgb(17, 0, 0)",
      "toolbar_field": "rgb(243, 246, 247)",
      "toolbar_field_text": "rgb(1, 39, 47)",
      "tab_line": "rgba(0, 10, 13, 0.59)",
      "popup": "rgb(243, 246, 247)",
      "popup_text": "rgb(0, 0, 10)",
      "button_background_active": "rgb(10, 182, 248)",
      "button_background_hover": "rgb(89, 183, 214)",
      "frame_inactive": "rgb(18, 198, 237)",
      "icons_attention": "rgb(4, 24, 64)",
      "icons": "rgb(2, 15, 40)",
      "ntp_background": "rgb(100, 140, 158)",
      "ntp_text": "rgb(0, 4, 11)",
      "popup_border": "rgb(4, 35, 64)",
      "popup_highlight_text": "rgb(1, 12, 17)",
      "popup_highlight": "rgb(200, 220, 230)",
      "sidebar_border": "rgb(100, 132, 158)",
      "sidebar_highlight": "rgb(100, 146, 158)",
      "tab_background_separator": "rgb(199, 199, 229)",
      "tab_loading": "rgb(1, 14, 43)",
      "tab_selected": "rgb(238, 245, 245)",
      "tab_text": "rgb(0, 0, 10)",
      "toolbar_bottom_separator": "rgb(0, 3, 11)",
      "toolbar_field_border_focus": "rgb(212, 212, 230)",
      "toolbar_field_border": "rgb(1, 4, 10)",
      "toolbar_field_highlight_text": "rgb(1, 6, 11)",
      "toolbar_field_highlight": "rgb(66, 198, 252)",
      "toolbar_field_separator": "rgb(197, 200, 218)",
      "toolbar_field_text_focus": "rgb(0, 4, 7)"
    }
  }
}