Use lighter menu hamburger icon on site without custom header?

Hello,

I’m working on a build using the Supernova starter site. I like everything about the header/primary navigation except the menu toggle which is a bit too heavyweight for the typography on the site. On other sites where I’ve used the custom GB site header element, I know there’s the option to switch to the lighter weight toggle icon. Is there any way to do this quickly and easy on a site such as Supernova where the custom site header element isn’t active?

Thank you!
Catherine