Lucky again, made it on the third hatch. Terrible DNA, but that is another story...
As you would expect, it comes in a spinning egg. When I saw a picture of the egg immediately after morphing, it was base medium blue with the hourglass and stripes in red; when I looked at it in my inventory the egg was still medium blue, but the markings had changed to a slightly darker blue.
The spider itself is black and gray... and waring a fruit hat a la Carmen Miranda.
Thanks again for the tip, Spiffy Michelle and Spiffykelsey!