Lineart is Neara's, not mine
Dark steeds are Unicorns with darker coats and silver horns. It's very rare that a foal be born with a light coat or a gold horn and even rarer to have both.
There is no real difference between Mares and Stallions other than temperament. Mares are much more wild and dangerous, harder to tame. Stallions are more mellow and likely to approach. It is unknown why it is like this though. Mares are more likely to have red or orange markings or eyes while stallions are seen with blue and green markings and eyes. On the rarest of occasions there will be stallions that have red eyes and marking and vise-versa with mare, though this usually happens if a mare has twins.
I am the only artist and that probably won't change and Adoption form will appear on each adopt with different ways to adopt.