Death Wave Overlap?

I have a question regarding death wave effect. With perks and sub modules I have 7 death waves doing about x750~ dmg per wave.

I farm tier 11 to wave 7k regularly and my wave effects (the ring after the waves) remains unbroken till around wave 2k.

My question is, when the ring is active, it's red. And when death wave procs again with the next resulting wave effect, it's color turns to a mix of red and blue. Does the previous wave effect remain until spent? Do they overlap/stack? Or does the new wave effect cancel the previous one and take it's place whether it was finished absorbing dmg or not.