Hi @dominik,

To change this, simply add the following code snippet to your website:

.main-navigation .navbar-toggler span,
.main-navigation .navbar-toggler span::before,
.main-navigation .navbar-toggler span::after {
   background-color: #ff0000 !important; /* Choose your color here */
}

To add this code snippet to your site, we recommend that you paste it to the Custom CSS panel of your WordPress Customizer. Just go to your dashboard and navigate to “Appearance > Customize > Additional CSS”.
Pasting your code snippet there should do the trick for you.

Also, it’s important to remember that we usually share snippet only to solve issues with our theme. Any further request for CSS snippets will have to be part of a defect that needs to be fixed urgently.

Regards,