Hi,
Add the following code in the Customizer > General > Custom Codes > CSS

.elementor-element .ce-nav-menu .current-menu-item.menu-item a.ce-menu-item:before{
  background: #01dbc1; /* Add Color Code */
  opacity: 1 !important; /* Insert value from 0-1 to hide and display */
}

Thanks,

Hi,
Please use https://imgur.com for images and Vimeo for videos. The screenshot you’ve attached not working.

Thanks,

Hi,
Use the following code to make changes on the dot.

.elementor-element .ce-nav-menu .menu-item a.ce-menu-item:before{
  background: #01dbc1; /* Add Color Code */
  opacity: 1 !important; /* Insert value from 0-1 to hide and display */
}

Thanks,

Welcome!

This custom CSS allows the color of the dot to be changed – but what will allow the colour of the pulse effect around the dot to also be changed?

Yes, via Custom css possible.