Did your family have any ties to a particular forest region in the past?

In the Sword Coast Adventurer's Guide, which 'caste' of elf (purely for RP purposes, not for rules in Player's Handbook) does the Elthrai clan fit into best? They list the elve casts on page 105.

Let me know what color dragon you want to pick before next session. Blue and Green are traditionally lawful evil and would be more apt to act like the dragon that granted a boon to the family. The other chromatic dragons tend to be chaotic evil. However, you can pick any color you'd like that you can choose per the PHB.