The characteristics are the color, pattern, clear belly, and the intensified color down the center of the back.
The base color as babies is really black...not brown. As the animals grow blushing appears where there is the black background giving them a faded brown look. Another interesting characteristic on these animals is they have the faded brown blushing but the 'flames' coming up off of the belly are silver/grey. The color down the center of the back is more electric as babies and stays more intense into adulthood. If you look at the top pic you can see the yellow is brighter right down the center of the back than on the rest of the body. I have noticed the breeder males change colors from day to night and they really get very light at night. Not sure if it's a breeding mode thing or what but it's a tremendous difference that makes them appear ghostly.
The pattern is obviously different from the norm and the characteristics include: No normal alien heads so to speak, larger hollowed out area within the pattern, speckling throughout the pattern, 'hooks' in the pattern, the pattern crossing over the back in many places and connecting with the pattern on the other side, and a fine pin line on the inside of the pattern like seen in Black pastels but more of it.
I'll try and dig up some color change stuff!