Here is a drawing of a SpaceWing.

Special features:
Front-facing horns
Spikes in their backs
Have a vaccum-like suction on their tail that sucks out air from things
The don't need air to live
They eat on a monthly basis (Euphemia from my book doesn't, because she hatched in Pyrrhia and eats everyday)

Colours for them:
Colour/colors for them may vary, but their scales are metallic
Their horns have a gradient of their scale colour, from dark to light starting from bottom

(Ps: their ancestors consist of NightWings and RainWings, but they breed perfectly well with any other dragon. Note; they do not have the features of a RainWing eg. No webbed ears or venom)

I did make them a little bit OP, but they live in Space for moon's sake! They haven't got trees, flowers, animals or any meat! All they eat is some scavengers they find in metal tubes with wings. (Astronauts in spaceships) Only royal blood gets water and the "good scavenger meat". The rest get the scavenger's dried food. (Like space ice cream or something)