In The Lord of the Rings, we know of the five Istari sent to Middle-earth to help resist Sauron. There was Saruman, the White; Gandalf, the Grey; Radagast, the Brown; and Alatar and Pallando, the Blue.
As per this answer, we know that the Blue wizards seemed to have traveled together to the East, and that their mission seemed to have been unsuccessful.
The question is--why were they both blue? Saruman is white; Gandalf is grey; Radagast is brown. Why were the remaining two the same color?
I'd be curious about answers both in-universe and out.