Updated list:
Chromatic Dragons (black, blue, green, red, and white)
Metallic Dragons (brass, bronze, copper, gold, and silver)
Lesser Dragon (drakes, turtle dragons, lightning heads, pseudodragons, draconis wyverns, etc.)
Mystic Dragons (faerie dragon, shadow dragon, force dragon, fang dragon, etc.)
Gem Dragons (onyx dragon, jade dragon, ruby dragon, amber dragon, crystal dragon, etc.)
Planar Dragons (astral dragon, ethereal dragon, styx dragon, radiant dragon, etc.)
Element Dragons (grey dragon, cloud dragon, sand dragon, yellow dragon, etc.)
A note that typical wyverns are not dragons, but they are beasts in the same category as griffon. The wyverns that have a draconic color and a breath weapon pseudo dragons.
Thoughts?