JQuery does not work on WordPress page.

try:

<script>
color = jQuery(“#colorPicker”).val()
</script>

Why would jQuery work but not $? The WP jQuery runs in noConflict mode. See my user note (the second one in the list) on the docs page.
https://developer.www.ads-software.com/reference/functions/wp_enqueue_script/
Sorry I cannot deep link right to the note, the example hiding code on the page messes up deep links.

Thanks for your advice! Now it works on my website https://www.playpianotips.com/