Each Dragon uses Armor specific to that Dragon type. You will note these by the symbol in the upper left corner of the armor piece.
Dragon Armor Edit
There are 4 main parts to any dragons set of armor, Body, Helmet, Clawguard and Tailguard.
There are 5 main materials that dragon armor comes in, Iron, Steel, Orichalc, Enchanted, and Exalted. The effect of these materials are outlined in Armor Attributes. The materials also present a different look to each dragon except in the case of the Earth and Fire Dragons where Iron and Steel both look the same. Higher quality material usually has better stats than the lower quality material.
Stats on armor pieces are derived from 4 parts to each piece of armor, Prefix, Material, Piece, and Suffix. These are outlined in Armor Attributes. The way that stats are decided on a piece is that each part has a window that those stats will fall into. The item is decided and a stat roll is made to determine what the stats are for that particular piece. This means if you have 2 pieces with the exact same name and rarity, it will likely still have different stats based on the roll for each. This also means that Material and Rarity do not absolutely mean better item. You could have 2 items with exactly the same name but one is uncommon (green) and the other is rare (blue) and the stats on the green item be better than those on the blue. This is because the green item rolled high for its stats while the blue got a low roll.
I have only seen common (white/gray), uncommon (green), rare (blue), and legendary (orange) gear in game. Legendary gear are usually parts of a set and normally are only obtained through rubies during special events. The other three rarities can be obtained through the Superior (Named) Dragon Chest, either by fighting Grodz or purchased with rubies. Items in the Superior Dragon Chests are completely random other than by name for that dragon.