mostly gray with some green and blue in it and some spots im sure it varys a bit he sifts sand pretty much 24hrs a day hes the whole reason my sand is decent, not sure about his tank req. mines in a 180 had him started in a 60 and when he seemed like a good addition i stuck him in my display tank and hes probably one of the best investments in there
heres a brief bio on them i found:
There are many different types of gobies out there and while the name Dragon Goby sounds a little intimidating don’t be alarmed. This type of goby serves a specific purpose in a saltwater aquarium. The Dragon Goby is known by several names which may seem a little less threatening to the average person such as, Brown-barred Goby, Pennant Goby, Harbor Goby or even Pistol Goby to name a few. No matter what you call this goby the colors are going to be the same. It has a light brownish gray body with dark bars on it. Also there are black spots on the gill cover, first dorsal fin and the tail with some blue spots on the front of the body and the head. The main purpose for having this particular fish is sifting the sand on the bottom of your tank. “What makes this goby different from all the others?” you ask.
The Dragon Goby is generally a hardier type of goby than most others like it. This goby will keep the upper layer of sand mixed up by consuming mouthfuls of sand and pushing it right back out through it’s gills. The average size for this fish is between 2-4 inches and the minimum tank size you can house it in is 20 gallons.
Their diet is pretty simple as well. It consists of small bottom dwelling invertebrates and algae. However, a varied diet is needed consisting of frozen food designed for invertebrates. Don’t be alarmed when you read that it eats bottom dwelling invertebrates that it may eat your star fish or any other invertebrates you may have in your aquarium because it is totally compatible with reef aquariums as well as non-reef aquariums. It will not harm sessile invertebrates.