How to emulate the work of the event “storage” when data should be transferred from a different HTML-file

I created a main HTML page of a calendar. On this page, I added the link to another HTML page for settings. On the settings page, a user has the option to choose the color of the events saved in the calendar. My goal is to make a user’s setting of a color be transferred to the calendar and change the display of its events elements immediately after the color is selected with the help of the input of the type “color” on the settings page. Basically, I need something like the event “storage” when it works for the same page opened in different tabs but in this case I want to deliver the value from the browser local storage to the main page immediately after the change of this value on the settings page. How can I establish an event listener on the main page reacting to the change on another page?

P.S. I need to do it with JavaScript.