Oh wow... I've seen like, really pale blue but nothing that vibrant. One time a really bright orange but usually white, pale yellows or greens and occasional blue.
I was responding to someone on another site that had the pale blue just yesterday.
It does happen from time to time. As long as it isn't a regular occurrence, I wouldn't be too concerned. I've also noticed that sometimes bedding seems to be an issue? Where the urate is is an off white but the bedding can seem to affect the color on the outside at times. I've seen that on cocofiber. Dunno if it has to do with the tanins leeching against it.
Something that bright as was mentioned, probably had to do more with something the feeder ate... But if this happens regularly or the snake starts to behave differently, I would ask for a vet's opinion and consider a blood test