I'm very familiar on how to create a hunger bar, but how would I create a hunger bar that shows, let's just say a hamburger, that grays out as the hunger of a player goes down. I just need a couple of hints, not really a complete answer.
Just put the gray image with the zindex higher than the colored image in a frame that is directly over the colored image and has clipdescendants on (which basically "cuts" any part of the gray image that is outside of the frame), then resize the frame as you would resize the gray image (although if youre using scale measurements in position and size things might get complicated).
If you don't understand what I'm saying, I suggest experimenting with the ClipDescendants property (a nice video that might give you an insight on how it works: https://www.youtube.com/watch?v=yz00YFZNBXQ)
I'm pretty sure this wouldn't be possible just THAT way. But the way to do this is just basically by actually editing a copy of the HamBurger image changing the color of it. Cutting it. And then once your hunger value reaches a certain amount, it will then display the gray hamburger image on top of the original one. But you'd just need to copy the original image, use Paint.NET or PhotoShop and then cut half of it to give that Hunger image effect. It's hard to explain but I hope you succeed in what you are trying to do!