does any one know how to change the vanish ghost sign color and sound effect please?

"Sound effect to use when vanishing": "assets/prefabs/npc/patrol helicopter/effects/rocket_fire.prefab",
"Sound effect to use when reappearing": "assets/prefabs/npc/patrol helicopter/effects/rocket_fire.prefab",
"Icon URL (.png or .jpg)": "http://i.imgur.com/Gr5G3YI.png",

Change the sound effect by using different asset effects in the config.

You can change the colour by downloading the image changing the colour and adding a new link.