Could be any number of things. It could have been too close to a heat/ice pack, to far from it, not quite healed enough before shipped, so on. I would put it under lower light, 100-200 par, and leave it. I have had this issue with some sticks I have been shipped. About 70% success rate bringing them back. It may take 1-2 months for them to get some color back and longer (5 months minimum) to look ideal. My preferred method of checking progress is to use something like fritz glasses to view them under actinics. The glasses will still look white to the eye, but the glasses will exaggerate the color and show the recovery. Most brown or orange lense glasses will have a similar effect.
As others have said, I do like to send a picture to the vendor to let them know how it arrived in the event it turns quickly. As for does this happen often, in my experience there is about a 10-15% chance of them arriving brown or white, granted most of my shipments of sps have been during winter with temps slightly above freezing.