Game Mechanics: Green mobs turn light blue

[sineroth]

hello i was slaying in crushbone lastnite i was lvl 8 and about to ding lvl 9 there was a group of 3 mobs 2 green cons and 1 bark blue con (never saw a light blue con during lvl's 1-8) i proceeded to slay the dark blue con and dinged lvl 9 as soon as i dinged the 2 green con mobs immediatly turned to light blue cons and they attacked me i dunno if thats how its suppose to work but i dont think so
thanks 4 the server