Player Killing Cape has received an overhaul and now has a fresh look, in addition to the cosmetic update we have added more colour options for the hardcore pk'ers! If you have 500 skulled kills (the opponent you've killed was skulled), you will have access to the new exclusive colours of the cape.
The cape benefits are the same, you can add super sets to your cape, so you don't need to carry pots into p2p wildy.
Player Killing Cape can be obtained for 500k by talking to Mad Zenok, if you have the 500 skulled kills, he will open a store window to pick the colours you want.
Amount or skulled kills you have can be found in characters high scores in server statistics section as "skulled_kills", if there are no skulled kills listed, then you did not have any skulled kills after the statistics gathering has been added this week.