My novel Draco’s Child features one dragon. Before the Fire Beast Falls has a whole planet full of them!
These dragons live on a (fictional) planet in the Goldilocks Zone of a star called Sigma Draconis, or Alsafi, which is a dim orange star in what we see as the constellation Draco. They look a lot like velociraptors with wings, no feathers, and without the killing claw, because they are civilized and reasonable. Most of the time, anyway. Usually. If no one pushes them too far.
They come in 8 colours, each with its own set of primary characteristics. The colours have a genetic hierarchy, which means that, for example, a Leaf dragon (green) mating with a Snow dragon (white), will normally have a Leaf hatchling because Leaf is higher than Snow on the hierarchy. But it depends on who the Leaf’s parents were as well, and which recessive colour gene the Leaf has. Figuring out all the probabilities can get quite complicated, if for example, you wanted to decorate the hatchling’s nest in advance.
Fortunately, Richard Hamilton wrote a computer program which you can try out on his website, to make it easy to find out. Just select the colours of the parents, and presto! You will get a list of how likely they are to hatch a dragon of each colour. You will also find out details about what the various colours of dragons are like, and what their particular strengths are.
To find out more, read the book!