It would almost definetely be a chestnut but an extreme anomaly can occur and the horse could even turn out to be dun under conditions of about 50'000 to 1
You need to put it in the fridge for 2-4 months (to symbolise winter). After that you need to plant it into a small pot and plant it about 1 inch deep leave it 1 month to germinate and as it grows...
Yes. Put the walnut in the ground, water it, keep it in the right climate and weather, care for it, and eventually you will grow a chestnut tree with chestnuts.
Chestnut is including chinkapin, a genus of eight or nine species of deciduous trees and shrubs in the beech family Fagaceae, native to temperate regions of the Northern Hemisphere