Could it not be that the Blue Wizards are blue because they came to Middle Earth by boat from the sea? Or possibly in order to get those who rebelled against Sauron to trust them? Since no servant of Melkor or Sauron would DEIGN to wear blue, as well as since blue signifies loyalty, truth, and calmness, and other stuff? And could it also be that Orome wore blue himself? Or that Manwe commanded them to wear blue to signify their allegiance to Eru and himself?

Could it not be that the Blue Wizards are blue because they came to Middle-earth by boat from the sea? Or possibly in order to get those who rebelled against Sauron to trust them? Since no servant of Melkor or Sauron would deign to wear blue, as well as since blue signifies loyalty, truth, and calmness, and other stuff? And could it also be that Oromë wore blue himself? Or that Manwë commanded them to wear blue to signify their allegiance to Eru and himself?