Shadow Ghoul is an armour you can buy from Yulgar's shop. You can colour customize it by going upstairs in Yulgar's Inn and then it says "Customize Character" and "Customize Armour". Then you click customize armour and change the colour if you want to. You can't enhance this armour, but it is a really nice armour. It looks like this. That's all I know about it, besides the fact that it can be bought for 27, 000 gold.