You can use COtobo to disconnect quickly after killing them (if you can 1-hit them), and then when you log back in, you won't be blue-name.
Also, if you're in TC, you can use FurnitureNPC to teleport out if you're quick enough.
Oh, and by the way, welcome to the forums and next time you should post questions in the right forum (CO2 Main) instead of in the Bots and Macros section.