Indeed. Transparency like the shades have.
For those who are wondering what they do look like, here's me in a full set:
What it basically is is that you go to an invisible ghost near glarial's tomb which you must wear the ring of visibility to see, and wear the amulet of ghostspeak to hear. He'll give you a piece of the clothing, and tell you where to find the next ghost. There are 6 altogether, and they give you the clothing in the following order:
Top, gloves, boots, legs, hood, and cape.
There are no fees, and they even give you a history lesson to the evil god Zamorak, which an interesting ending as to what became of the 'Empty Lord'.
WARNING: Sonetimes you will be led to the wilderness. I had to navigate through the lava maze to get to one. Plus, they are different for everyone, and hard to see on the screen, as they don't show up on the map, so keep your eyes peeled.