In my phaseship, I used pink fog, which I changed more and less transparent (IIRC). But I suppose adding a plane on top of the ship, which is transparent, and changes to pink gradually.
You could try those. Or I could
[EDIT]
Yep, you could do it by putting a plane like this
plane {y, 120 rotate x*-20 pigment {color rgbft <1,0,1,0+.2*clock,1-.8*clock>} finish {ambient 1 diffuse 1}}
It makes the item under it disappear almost completely. If you want to make it disappear completely, just change the .8*clock to 1*clock. The height and rotate x you should determine so, that the image looks like there's no plane in front of it (when the filter & transparency-values are 0 an 1, respectively).
). So what I'm making now look's like Tetra's ship (and it will be), but I'll be making the Ghost Ship version first, why? Cause it'll be harder.
) Lookin' good so far, 
