High PDR seems to effect the Spit Attack's DoT

Was having a conversation with a friend about poison damage and they remarked how they have noticed a high PDR effecting the DoT from the Centipedes Spit Attack, but not its Poison Trail. After doing a little investigation I noticed that all sources of poison damage outside of Death Beetles and Goblin Weapons is Green. Zombie and Stinky Stick gas, the Dragon fly attack, and the Centipedes Poison Trail. The Spit Attack, however, has a purply red color very similar to the Rogues "Rupture" ability

I trust my friends experience, so is it possible that the Spit Attack is actually a Physical Damage Bleeding effect? I will probably do more testing on this and reply here with my findings