You must buy a black pearl which costs 4 passes. They are currently out of stock though. Keep checking back to see if they are available.
You can make various coats for horse, including the Golden apple coats and diamond apple coats.
The coats are randomly selected from all possible coats for that breed.
They already have if you mean the horse coats, backgrounds and pet coats!
There is a topic in the 'Events' forum showing the coats.
Ask in the 'Retired GA Coats' topic or the 'Howrse Spotters' topic in the events forum on Howrse.
Howrse recently changed and updated the coats of each breed to Version 3.
You can submit as many coats/patterns as you wish...., but will have to pay to have them added to the game with a BLACK PEARL for each coat.
New coats are added every day.
no all coats are randomly selected by howrse.com
Howrse recently released a Version 3 of all the horse coats and got rid of all the previous version 1 and version 2.
No. If either or both of the parents have GA SA or DA coats, a random coat will be selected fromm among those allowed for the breed.
When you buy a golden apple from the black market, or win one through other activities, you can choose from player created coats.