---
description: |
  Converts the entire page to grayscale.
  <i class="gray">Toggles the page color on and off.</i>

####### Other Metadata #######
authors: |
  Bookmarklets <https://codepen.io/bookmarklets>
  Kyle Suttlemyre <https://github.com/ktsuttlemyre/RogueBookmarklets>
originalsource: https://cdpn.io/bookmarklets/fullpage/NobJbq

####### function signature #######
specs: stdout
layout: script

# for syntax see: https://jsdoc.app/tags-type.html
params: |
  {bool} on - turn on or off. If null or undefined it will toggle
returns: |
  {bool} isGrayscale
---
function i(i) {
  document.body.style.filter = i, document.body.style.webkitFilter = i;
}
if(on!=null){
  window.isGrayscale=!!on
}
window.isGrayscale ? (i("none"), window.isGrayscale = !1) : (i("grayscale(1)"), window.isGrayscale = !0);

return window.isGrayscale;