Change colour of menu hamburger icon

Hi Wes

I’m looking to change the background colour of the navigation bar and I think I’ve found all the places I need to do that but I’m having problems working out how to make the hamburger icon white and where to set the hover colour for it.

Could you give any pointers?

Also, is the theme likely to get an update for Gutenberg soon? If so, it might be better for me to wait for that before making many big changes.