A Masonic Blue Lodge (Facing East)

Why is it called a “Blue Lodge?”
Some authorities think that as blue has, from ancient Biblical times, been associated with truth, with Diety, with wisdom and hope; that, as Mackey taught, the blue of the Old Testament is a translation of the Hebrew “tekelet”, which is derived from a root meaning “perfection”, and the color blue came into Masonry as its color by natural association. 

Others believe that as our ancient Brethren met on hills and in vales, over which the blue vault of heaven is a ceiling, that the covering of a lodge is the clouded canopy or starry decked heaven. These allusions seem to connote that blue, the color of the sky, is that of all celestial attributes for which Freemasons strive. “

Brother Harry E. Heinkel from Henry L. Palmer Lodge No. 301, Milwaukee, asked the same question: “Why do we say ‘Blue Lodge’”? His findings are most interesting. At the risk of being termed a Masonic symbologist, he questioned and criticized the propriety of the term “Blue Lodge” when Freemasons speak of the Masonic Lodge of symbolic degrees: The term is peculiarly American; it is found nowhere else in the Masonic world. Evidence does not support the conclusion that the color Blue is the symbol of the three symbolic degrees of Ancient Craft Masonry, whether Operative or Speculative, in time immemorial or of the present. 

That “Blue” is a significant or characteristic symbol of Freemasonry is not supported by the ritual. No pointed reference is made to it ” in the three symbolic degrees. “Blue is emphatically the color of Freemasonry,” wrote one authority. But the color of the United Grand Lodge of England is Garter (Oxford) Blue, while that of private (subordinate) lodges is Cambridge Blue, and the Grand Steward’s Lodges in London, known as the “Red Apron” Lodges use crimson, thought to be suggested by the color of the ribbon of the Order of the Bath. 
The color of the Grand Lodge of Scotland is thistle green, while daughter (subordinate) lodges adopt a color of their choice. The recently instituted Grand Lodge of India adopted three colors, the Garter Blue of England, the Thistle Green of Scotland and the Sky Blue of Ireland. This is in honor of the three Grand Lodges by whom it was instituted.

Could the color Blue have been adopted when Blue Ribbons were attached to the Aprons? Perhaps, but aprons which can be seen in the museum in Freemasons Hall,London are evidence that prior to and during the early years following the formation of the Grand Lodge in 1717, Aprons were white and of a considerable size. 
Rather than “Blue Lodge” Brother Heinkel prefers to proudly claim to be member of a “Masonic Lodge” which is understood by Freemasons and non-Masons throughout the world.

How and when the term “Blue Lodge” came to be known as the color of Freemasonry is yet to be discovered, but in present day usage, the term “Blue Lodge” identifies the membership and organization of Freemasons under the authority of the Grand Lodge.
The two theories which find the most believers are (1) the adoption of the color by early operative Freemasons because of an age-old association of blue with those virtues which are peculiarly Masonic (2) the adoption of the color by early Grand Lodge in imitation of the nobility and the fame of the color of the most famous Order of Knighthood in the world.
Anyone have another idea why?

D. References:The WI Freemason, Vol XVIII Mar 1962 No 7 P 12 “Why do we say ‘Blue Lodge’”