Has anyone else noticed that certain node titles in light and dark battles turn yellow?

Mugen9009

So I’ve noticed that sometimes every now and then the battle titles of the nodes in light and dark battle turn yellow. And when they turn yellow there’s a higher gear drop rate. There’s like a 90% chance I get the gear when it’s yellow. But I noticed its only temporary.Does anyone else know when or why the normal and hard battles in light and dark battle turn yellow??