White LEDs unfortunately do not all light with the same colour tint. Many appear blueish, some are purply, some are almost yellow or green. It`s just the natural variations that occur within the manufacturing processes, which are extremely difficult to control precisely. To get around this they get sorted by colour tint (and brightness) and assigned a "rank", which, often, manufacturers can specify when ordering their LEDs.
I was under the impression that Photon used LEDs that were from a less blueish rank (maybe B1), but occasionally one odd one will get through the sorting process, or perhaps they experienced a shortage of the desired rank and had to make do with an alternative for a little while.
If you don`t like the purply tint you can always take advantage of LRI`s great customer satisfaction guarantee- I reckon they`d accept a return for a refund or perhaps an exchange- and see if the replacement has a better colour. But if it`s not too much of a problem to you, don`t worry- it`s a common occurance.
Incidentally one of my white Arc-AAAs (the normal black bodied one, not the LE) has a distinctive purple tint to the beam. Another is a lot whiter, just a little blueish.