Triskelion27

Brilliant, thank you MayaViolet!

Try changing the last line of code to the following:
 
.header-menu-nav-item a:hover div { color: red !important; }  
You can also add a transition property if you'd like the color to fade in and out on hover:
 
.header-menu-nav-item a:hover div, .header-menu-nav-item a div { -webkit-transition: .5s; -o-transition: .5s; transition: .5s; }  

Yes a URL will help solve the issue...

Your CSS code should work, but more than likely its not because of another line somewhere conflicting the css...

What is site url? We can check easier

This should work for you:
.burger-inner:hover .top-bun, .burger-inner:hover .patty, .burger-inner:hover .bottom-bun {background-color:red !important;}