Did Roger Zelazny ever give a reason for using the name "Amber" in the Chronicles of Amber series?
I'm looking for his out-of-universe thinking. If anyone can find the in-universe history of the name "Amber," that would be interesting too.
The first novel was called 'Nine Princes in Amber', and there appears to be a pun in the title. All nine princes - as well as their sisters - are represented by the cards which preserve their image from a specific moment in time; also Amber is the 'real' reality and the others, including ours, are only shadows, and its image is preserved in the original pattern created by Dworkin. So in a sense the pattern preserves Amber and the princes; and as amber can be damaged, so can the original pattern.
Zelazny wrote in a 1967 letter to fellow writer Andre Norton that the title Nine Princes in Amber had dual intent. First, it referred to the city itself with the influences that it would have on the people there. Second, it referred to characters embedded like insects in amber – “individuals frozen in timeless moments of some particular passion or phase of their lives, as though contained like one of those insects.”
For reference and for more of his thoughts about creating the Amber series, see: "...And Call Me Roger": The Literary Life of Roger Zelazny, Part Two, by Christopher S. Kovacs. In: THE COLLECTED STORIES OF ROGER ZELAZNY: VOLUME TWO: POWER & LIGHT, NESFA Press, 2009.
There is also the metaphysical contrast of chaos and order, where ultimate chaos is frenetic, dynamic, and eternally inconsistent while ultimate order is unchanging as if it were frozen in amber.
The pattern in Amber, the thing that gives it it's "Amber-ness" is not the primal pattern, but is one step away from it. Even the primal pattern itself, it could be argued, is not self-existent but is a copy of the more primal pattern within the unicorns horn, that is mixed with some primal identity of the person creating the "new" pattern.
Only someone "of" the pattern, can walk the pattern - this is why being of Royal Amber blood is a prerequisite (one of several) to being able to successfully walk the pattern.
The courts of Chaos are at the edge of pure Chaos, only non-physical beings like the ty-iga, can live over the edge. Just as there is no life inside the infinitely unchanging order, there is also no life in the infinitely changing chaos. Life is lived between the two.
The equal but opposite of the "Pattern of Amber" is the Logrus. While the Pattern is created by the Unicorn, the Logrus is created by the Serpent.
In the same way as the pattern, only a being who is "of" the Logrus, a "Chaosian" noble house, is able to successfully traverse the logrus and gain its version of the ability to transit the shadow/multiverse, and such.
One of the big questions that defined both Corwin, and Merlin, that speaks to what "Amber" means is their quest for their fathers, and for their place in the world of their fathers. Corwin tries to fight and find his place in context of Oberon, and the court that Oberon left behind. Merlin looks for Corwin. There is part of each of them, that is looking for the place where they came from, that is seeking to understand, and transform their roots. The process of exploration is like the battle between the Pattern and the Logrus in the microcosm of their inner persons.
The question behind Corwin is about whether or not his identity is "set in amber" and to what degree he can influence its final state. There is an "internal amber" that comes into play as well.
Zelazny stated explicitly that he began Nine Princes in Amber with absolutely no idea where the story would go: no concept of the cosmology, or the family, or pretty much anything. Everything was made up as he went along. So "Amber" was probably just a name he pulled out of thin air; at most, he may have conceived of the punny title of the first book when he decided upon the city's name.