This armor seems to be made from old, worn dragon scales, which give it a pleasantly rustic look.

This suit of +1 dragonhide full plate is made from cast-off scales rather than the hide of a slain dragon. While wearing it, you have resistance 10 against the form of energy associated with the breath weapon of the dragon that provided the scales (such as fire, in the case of red dragonrider armor). You also gain a +5 competence bonus on Ride checks you make while riding any creature of the dragon type.
In addition, dragonrider armor automatically produces a feather fall effect (as the feather fall spell) if you fall more than 5 feet while wearing it.

Prerequisites: Craft Magic Arms and Armor, cat’s grace.
Cost to Create: 9,000 gp (plus 300 gp for base item), 720 XP, 18 days.