The breed doesn't have any colour or marking specifications. Colours of bay, chestnut, flaxen chestnut, black, gray and variety of roans have been recorded since they also exist in purebreds. In extreme cases, a horse may have multiple facial markings and all legs marked with white. Open studbook policy has led to pinto (piebald) pattern; one female family used in "ban'ei" can be traced to single stallion born in 1967, while dominant white seen in two horses was spontaneous, manifesting in 2010. Prevalence of hereditary diseases is unknown, since at least one Western scientific source lists breed as "ban-ei" without hereditary diseases.