{
  "resources": {
    "body": [
      {
        "type": "script",
        "src": "./instantclick.js"
      },
      {
        "type": "script",
        "contents": "InstantClick.init(); if (INSTALL_OPTIONS.progressBar !== true) { document.head.insertAdjacentHTML('beforeend', '<style>#instantclick { display: none; }</style>'); } else { if (INSTALL_OPTIONS.progressBarColor) { document.head.insertAdjacentHTML('beforeend', '<style>#instantclick-bar { background-color: ' + INSTALL_OPTIONS.progressBarColor + '; }</style>'); } }"
      }
    ]
  },
  "options": {
    "properties": {
      "progressBar": {
        "description": "When navigating from one page to another, show a loading progress bar at the top of the page.",
        "title": "Show progress bar",
        "type": "boolean"
      },
      "progressBarColor": {
        "default": "#2299dd",
        "description": "The color of the progress bar. (Requires \"Show progress bar\" to be checked.)",
        "format": "color",
        "title": "Progress bar color",
        "type": "string"
      }
    }
  }
}

{
  "resources": {
    "body": [
      {
        "type": "script",
        "src": "./instantclick.js"
      },
      {
        "type": "script",
        "contents": "InstantClick.init(); if (INSTALL_OPTIONS.progressBar !== true) { document.head.insertAdjacentHTML('beforeend', '<style>#instantclick { display: none; }</style>'); } else { if (INSTALL_OPTIONS.progressBarColor) { document.head.insertAdjacentHTML('beforeend', '<style>#instantclick-bar { background-color: ' + INSTALL_OPTIONS.progressBarColor + '; }</style>'); } }"
      }
    ]
  },
  "options": {
    "properties": {
      "progressBar": {
        "order": 1,
        "description": "When navigating from one page to another, show a loading progress bar at the top of the page.",
        "title": "Show progress bar",
        "type": "boolean"
      },
      "progressBarColor": {
        "order": 2,
        "showIf": {
          "progressBar": true
        },
        "default": "#2299dd",
        "format": "color",
        "title": "Progress bar color",
        "type": "string"
      }
    }
  }
}

Use showIf for progress bar color @zackbloom
Use showIf for progress bar color @zackbloom