Strange UI effect happening to my inventory

There's like a glowy transparency thing going on and that makes it really hard to see like half of my inventory during day time :( Also as a sidenote, my frames are dropping to weirdly low rates during certain moments (e.g. Providence Phase 2, certain Empress of Light attacks) even though I've got a really good PC. I've also done the thing where I go into the config.json and change some stack load thingy to 6,400,000 but there isn't a huge change...