You still haven’t shown your nightvision- just how you toggle it.
Also, for something like this, you should definitely use a set members node.
You can put it in a function, but it shouldn’t be a variable.
Every single time you want to change how the normal mode looks, you’ll have to replicate those changes in night vision as well- not to mention how annoying that would be if you ever have anything more than just night-vision and normal mode.
Here’s how you can do it in case you’re not sure:
Also unless your sound is global, you should probably set the location it’s playing at.