On a standalone kali vm, when I type my gateway for sys firewall it turns yellow. When I try to connect it doesn’t work. Help needed.
could you give us additional info? like everything you can think of… the more the better 
Assume, you’re on Qubes 4.1 and the SAlone Kali VM can’t understand, why your VM IP is 10.137.0.xxx and your Gateway will have 10.138.13.103… So this is, why it turns yellow I guess.
You can solve this, if you change the Subnetmask to 255.255.0.0
It works for me and all my standalone qubes.
I realized my connection was automatic not manual so i fixed it myself.