You mean the enchantment glow?
That's not just a 1.15 thing lol
I don't particularly like it either, it's pretty easy to throw together a resource pack that gets rid of it, just add a pure black texture for the enchantment glow.
I keep mine as a really faded green glow, I find it far less off-putting, but it's still nice to be able to see when an item's enchanted or not